- String-Math 2016, 27 June - 2 July 2016, Collège de France, Paris. (Member of the organizing committee.)

- AMS Algebraic Geometry Summer Research Institute, 12-31 July 2015, University of Utah.
- Gravity, Strings, and Holography in honor of Gary Horowitz, 1-2 May 2015, UCSB.

- Grassmannian Geometry of Scattering Amplitudes, 8-12 December 2014, Walter Burke Institute, Cal Tech.
- Blackwell-Tapia Conference and Awards Ceremony, 14-15 November 2014, IPAM, UCLA.
- Gauged Sigma-Models in Two Dimensions, 3-7 November 2014, Simons Center for Geometry and Physics, SUNY Stony Brook.
- AGNES, 31 October - 2 November 2014, University of Pennsylvania.
- WAGS Fall 2014, 11-12 Ocboter 2014, University of Idaho.
- Workshop on G2 Manifolds, 2-5 September 2014, Simons Center for Geometry and Physics, SUNY Stony Brook.
- Program on G2 Manifolds, 18 August - 3 October 2014, Simons Center for Geometry and Physics, SUNY Stony Brook.
- International Congress of Mathematicians, 13-21 August 2014, Seoul.
- 2014 Simons Summer Workshop in Mathematics and Physics, 21 July - 15 August 2014, Simons Center for Geometry and Physics, SUNY Stony Brook.
- Emergent Spacetime in String Theory, 6 July - 3 August 2014, Aspen Center for Physics.
- Amsterdam String Workshop 2014, 30 June - 11 July 2014, Center for Mathematical Physics, Amsterdam.
- Strings 2014, 23-27 June 2014, Princeton.
- Workshop on Calabi-Yau manifolds and their moduli, 14-18 June 2014, University of Alberta.
- String-Math 2014, 9-13 June 2014, University of Alberta.
- Heterotic Strings and (0,2) QFT, 28 April - 02 May 2014, Mitchell Institute, Texas A & M University. (Member of the organizing committee.)
- Special Session on Singularities and Physics, 21-23 March 2014, American Mathematical Society Southeastern Sectional Meeting, Knoxville, Tennessee.
- From the Renormalization Group to Quantum Gravity: Celebrating the science of Joe Polchinski, 27-28 February 2014, KITP.
- Geometry and Physics of F-Theory, 24-27 February 2014, Heidelberg University.
- Quantum Fields beyond Perturbation Theory, 27-31 January 2014, KITP.
- 2014 Joint Mathematics Meetings, 15-18 January 2014, Baltimore.
- Rikkyo MathPhys 2014, 11-13 January 2014, Rikkyo University.
- New Methods in Nonperturbative Quantum Field Theory, 6 January - 11 April 2014, KITP.

- Hodge Theory in String Theory, 18-22 November 2013, Fields Institute, Toronto. (Member of the organizing committee.)
- Mock Modular Forms, Moonshine, and String Theory, 26-30 August 2013, Simons Center for Geometry and Physics, SUNY Stony Brook.
- Black Holes: Complementarity, Fuzz, or Fire?, 19-30 August 2013, KITP.
- 2013 Simons Summer Workshop in Mathematics and Physics, 22 July - 16 August 2013, Simons Center for Geometry and Physics, SUNY Stony Brook.
- Mathematics of superconformal field theory, 7 July - 4 August 2013, Aspen Center for Physics.
- Strings 2013, 24-28 June 2013, Seoul, Korea.
- Development of Moduli Theory, 11-21 June 2013, RIMS, Kyoto University.
- Snowmass on the Pacific, 29-31 May 2013, KITP.
- Algebraic Geometry Conference in honor of Rob Lazarsfeld's 60th birthday, 16-19 May 2013, University of Michigan.
- Hodge theory and classical algebraic geometry, 13-15 May 2013, Ohio State University.
- Geometry and Physics of Gauged Linear Sigma Model, 4-8 March 2013, University of Michigan.
- Seminar weeks on Calabi-Yau manifolds, mirror symmetry, and derived categories, 15-23 February 2013, University of Tokyo.
- 2013 Joint Mathematics Meetings, 9-12 January 2013, San Diego.
- The Search for Fundamental Physics: Higgs Bosons and Supersymmetry, 4-6 January 2013, U.C. Santa Cruz.

- Mirror Symmetry in the Midwest, II, 8-11 November 2012, University of Wisconsin, Madison.
- WAGS Fall 2012, 20-21 October 2012, University of Utah.
- Syzygies in Algebraic Geometry, with an exploration of a connection with String Theory, 12-17 August 2012, Banff International Research Station.
- 2012 Simons Summer Workshop in Mathematics and Physics, 30 July - 17 August 2012, Simons Center for Geometry and Physics, SUNY Stony Brook.
- International Conference on Geometry And Analysis On Manifolds, 16-18 July 2012, UCSB.
- Exact Results in Gauge Theory and Their Applications, 1-22 July 2012, Aspen Center for Physics.
- Knotted Fields, 18 June - 14 July 2012, KITP.
- Algebraic Topology, Field Theory and Strings, 21-25 May 2012, Simons Center for Geometry and Physics.
- String Phenomenology, 23-27 April 2012, Simons Center for Geometry and Physics. (Member of the organizing committee.)
- F- Theory, 19-23 March 2012, Simons Center for Geometry and Physics. (Member of the organizing committee.)
- OSU/UIC/UM Algebraic Geometry Workshop, 10-11 March 2012, Ohio State University.
- 2012 Joint Mathematics Meetings, 4-7 January 2012, Boston.
- Simons Center Program on String Compactification, Spring Semester 2012, Simons Center for Geometry and Physics. (Member of the organizing committee.)

- Noncommutative algebraic geometry and D-branes, 12-16 December 2011, Simons Center for Geometry and Physics.
- Hodge Theory and String Duality, 4-9 December 2011, Banff International Research Station.
- Mirror Symmetry in the Midwest, 3-6 November 2011, Kansas State University.
- Algebraic Geometry for String Theorists, 10-14 October 2011, Arnold Sommerfeld Center for Theoretical Physics, Munich.
- A Celebration of Algebraic Geometry: A Conference in Honor of Joe Harris' 60th Birthday, 25-28 August 2011, Harvard University.
- Holography and Singularities in String Theory and Quantum Gravity, 24 July - 21 August 2011, Aspen Center for Physics.
- Nonperturbative Effects and Dualities in QFT and Integrable Systems, 11 July - 26 August 2011, KITP. (Member of the organizing committee.)
- Mirror Symmetry & Tropical Geometry, 2-8 July 2011, Cetraro, Italy.
- MMP and Extremal Rays, 20-24 June 2011, RIMS, Kyoto University.
- Number Theory and Physics at the Crossroads, 8-13 May 2011, Banff International Research Station.
- Southern California Strings Seminar, 6 May 2011, USC.
- 2011 Joint Mathematics Meetings, 6-9 January 2011, New Orleans.

- RIMS International Conference on Noncommutative Geometry and Physics and Hayashibara forum on Symplectic Geometry, Noncommutative Geometry and Physics, 1-12 November 2010, RIMS, Kyoto University.
- Langlands-Type Dualities in Quantum Field Theory, 9-27 August 2010, KITP. (Member of the organizing committee.)
- Simons Workshop in Mathematics and Physics, 26 July - 20 August 2010, Simons Center for Geometry and Physics, SUNY Stony Brook.
- New Mathematical Methods in Quantum Gauge Theories, 27 June - 25 July 2010, Aspen Center for Physics.
- Connections in Geometry and Physics 2010, 7-9 May 2010, Perimeter Institute.
- String Vacuum Project, Spring 2010 meeting, 3-5 May 2010, KITP.
- Astronomy, Astrophysics & High Energy Physics Information Providers Summit IV, 15-16 April 2010, Harvard-Smithsonian Center for Astrophysics.
- Workshop on Generalized Geometries and String Theory, 25-28 March 2010, Brandeis University.
- Strings 2010, 15-19 March 2010, Texas A&M University.
- Workshop on Elliptic Fibrations and F-theory, 4-8 January 2010, IPMU. (Member of the organizing committee.)

- Mirror Symmetry and Gromov-Witten Invariants, 7-11 December, 2009, Graduate School of Mathematical Sciences, University of Tokyo.
- WAGS Fall 2009, 24-25 October, 2009, UCLA.
- Unity of String Theory, 26 July - 16 August 2008, Aspen Center for Physics.
- Quantum Criticality and the AdS/CFT Correspondence, 29 June - 24 July 2009, KITP.
- Confronting Challenges in Theoretical Physics, 15-16 June 2009, U. C. Santa Cruz.
- Perspectives in Mathematics and Physics, 22-24 May 2009, MIT.
- WAGS Spring 2009, 25-26 April 2009, U. C. Berkeley
- Combinatorial, Enumerative and Toric Geometry, 23-27 March 2009, MSRI.
- Mini-Conference on Dualities in Physics and Mathematics, 16-20 March 2009, KITP. (Member of the organizing committee.)
- MAA Sectional Meeting, 28 February 2009, MSRI.
- Modern Moduli Theory, 23-27 February 2009, MSRI.
- Algebraic Geometry, 12 January - 22 May 2009, MSRI.
- Fundamental Aspects of Superstring Theory, 5 January - 29 May 2009, KITP.

- Tropical Geometry and Mirror Symmetry, NSF-CBMS Conference, 13-17 December 2008, Kansas State University.
- Southern California Strings Seminar, 8-9 December 2008, USC.
- WAGS Fall 2008, 8-9 November 2008, University of Utah.
- Geometrical Aspects of String Theory, 20-24 October 2008, Nordita, Stockholm .
- Algebraic and Differential Geometry: A Conference in Celebration of the 70th Birthday of Phillip Griffiths, 16-17 October 2008, IAS.
- Topological strings: physics and geometry (WAGP08), 20-24 September, 2008, Center of Mathematical Sciences, Zhejiang University, Hangzhou, China.
- Gauge Theory and Langlands Duality, 21 July - 8 August 2008, KITP. (Member of the organizing committee.)
- Amsterdam Summer Workshop on String Theory, 7-11 July 2008, Center for Mathematical Physics, Amsterdam.
- Strings @ Amsterdam (Eurostrings 2008), 30 June - 4 July 2008, Center for Mathematical Physics, Amsterdam.
- Simons Workshop in Mathematics and Physics, 16 June - 12 July 2008, Simons Center for Geometry and Physics, SUNY Stony Brook.
- String Phenomenology 2008, 28 May - 1 June 2008, University of Pennsylvania.
- Geometric Flows in Mathematics and Physics, 13-18 April 2008, Banff International Research Station.
- 30 Years of Mathematical Methods in High Energy Physics, 17-19 March 2008, RIMS, Kyoto University.
- Workshop in Celebration of Mark Green's 60th Birthday: Hodge Theory and Algebraic Geometry, 22-23 February, 2008, IPAM.
- 2008 Joint Mathematics Meetings, 6-9 January 2008, San Diego.

- WAGS Fall 2007, 20-21 October 2007, Colorado State University.
- Simons Workshop in Mathematics and Physics, 30 July - 31 August 2007, SUNY Stony Brook.
- String Theory and Quantum Geometry, 2-29 July 2007, Aspen Center for Physics.
- WAGS Spring 2007, 28-29 April 2007, University of Washington.
- Conference on Lie Groups, Lie Algebras, and their Representations, 21-22 April 2007, University of California, Santa Barbara.
- Southern California Algebraic Geometry Seminar, 24 February 2007, University of California, San Diago.
- 2007 Joint Mathematics Meetings, 5-8 January 2007, New Orleans.

- Southern California Strings Seminar, 1-2 December 2006, University of California, Los Angeles.
- Blackwell-Tapia Conference, 3-4 November 2006, Institute for Mathematics and its Applications, University of Minnesota.
- AMS 2006 Fall Western Section Meeting, 7-8 October 2006, University of Utah.
- String Phenomenology 2006, 28 August - 1 September 2006, Kavli Institute for Theoretical Physics, University of California, Santa Barbara.
- Simons Workshop in Mathematics and Physics, 24 July - 25 August 2006, SUNY Stony Brook.
- Amsterdam Summer Workshop on String Theory, 3-13 July 2006, Center for Mathematical Physics, Amsterdam.
- New Developments in the Geometry and Physics of Gromov-Witten Theory, 22-26 May 2006, Mathematical Sciences Research Institute, Berkeley.
- Texas Algebraic Geometry Seminar, 19-21 May 2006, Texas A&M University.
- Generalized McKay Correspondences and Representation Theory, 20-24 March 2006, Mathematical Sciences Research Institute, Berkeley.
- WAGS Spring 2006, 18-19 March 2006, University of California, Berkeley.
- 2006 Joint Mathematics Meetings, 12-15 January 2006, San Antonio.

- Algebraic Geometry & Beyond, 12-16 December 2005, Kyoto University.
- WAGS Fall 2005, 3-4 December 2005, University of Utah.
- Mathematical Structures in String Theory, 1 August - 16 December, 2005, Kavli Institute for Theoretical Physics, U. C. Santa Barbara.
- Strings 2005, 11-16 July 2005, Toronto.
- Amsterdam String Theory Workshop, 15-22 June 2005, Center for Mathematical Physics, Amsterdam.
- World Digital Mathematical Library, 15-17 April 2005, Mathematical Sciences Research Institute, Berkeley.
- Periods: Around the Theory of Primitive Forms, 22-26 January 2005, RIMS, Kyoto University.
- 2005 Joint Mathematics Meetings, 5-8 January 2005, Atlanta.

- Mirror Symmetry Workshop, 19-23 November 2004, Perimeter Institute.
- Blackwell-Tapia Conference and Prize Presentation, 5-6 November 2004, Institute for Pure & Applied Mathematics, UCLA.
- Joint Mathematics Meetings, 7-10 January 2004, Phoenix.

- Geometry, Topology, and Strings, 14 July -- 8 August 2003, Kavli Institute for Theoretical Physics, U. C. Santa Barbara.
- Geometry and Physics of G2 Manifold, 29 April - 2 May, 2003, Institute for Pure & Applied Mathematics, UCLA.
- Joint Mathematics Meetings, 15-18 January 2003, Baltimore.

- Conference and Prize in Honor of David Blackwell and Richard A. Tapia, 1-2 November 2002, Mathematical Sciences Research Institute, Berkeley.
- Strings 2002, 15-20 July 2002, Cambridge University.
- Joint Mathematics Meetings, 6-9 January 2002, San Diego.

- JHS/60: A Meeting to Celebrate 60 Years of John H. Schwarz, 3-4 November 2001, California Institute of Technology.
- Extreme String Theory, 5 August - 9 September 2001, Aspen Center for Physics.
- Quantum Field Theory, Supersymmetry, and Enumerative Geometry, 8-28 July 2001, IAS/Park City Mathematics Institute, Park City, Utah. (Member of the organizing committee.)
- Duality Workshop: A Math-Physics Collaboration, 18 June - 13 July 2001, Institute for Theoretical Physics, U. C. Santa Barbara.
- Avatars of M-Theory, 5-8 June 2001, Institute for Theoretical Physics, U. C. Santa Barbara.
- M Theory, 29 January - 29 June 2001, Institute for Theoretical Physics, U. C. Santa Barbara.
- Strings 2001, 5-10 January 2001, Tata Institute for Fundamental Research, Mumbai, India.

- Computational Complexity Theory, 16 July - 5 August 2000, IAS/Park City Mathematics Institute, Institute for Advanced Study, Princeton.
- A Weekend of Algebraic Geometry in Celebration of Herb Clemens's 60th Birthday, 10-12 March 2000, University of Utah.

- The Future of Mathematical Communication 1999, 1-5 December 1999, Mathematical Sciences Research Institute, Berkeley.
- String Theory: Duality, Gravity & Field Theory, 23 August - 12 September 1999, Aspen Center for Physics.
- Workshop on Geometry and Physics, 26 July - 13 August 1999, Institute for Theoretical Physics, U. C. Santa Barbara. (Member of the organizing committee.)
- Santa Barbara Summer Conference in Geometry, 21-24 July 1999, U. C. Santa Barbara.
- Geometry and Physics of D-Branes, 28 June - 9 July 1999, IHES.
- Arithmetic Algebraic Geometry, 20 June - 10 July 1999, IAS/Park City Mathematics Institute, Park City, Utah.
- Mathematical Aspects of String Theory, 18-24 April 1999, Mathematisches Forschungsinstitut Oberwolfach. (Member of the organizing committee.)

- Representation Theory of Lie Groups, 12 July - 1 August 1998, IAS/Park City Mathematics Institute, Park City, Utah.
- Strings '98, 22-27 June 1998, Institute for Theoretical Physics, U. C. Santa Barbara.
- Dualities in String Theory, 20 January - 26 June 1998, Institute for Theoretical Physics, U. C. Santa Barbara.
- Geometry and Duality, 12-30 January 1998, Institute for Theoretical Physics, U. C. Santa Barbara. (Member of the organizing committee.)

- Complex Geometry: Relations with Mathematical Physics, 24-30 August 1997, Mathematisches Forschungsinstitut Oberwolfach.
- Duality, 14 July - 9 August 1997, Aspen Center for Physics.
- Symplectic Geometry, 29 June - 19 July 1997, IAS/Park City Mathematics Institute, Park City, Utah.
- Strings '97, 16-21 June, 1997, University of Amsterdam.

- Four Dimensionsal Geometry and Quantum Field Theory, 4 November - 13 December 1996, Isaac Newton Institute for Mathematical Sciences, Cambridge University.
- Duality in Physics and Mathematics, 22 July - 18 August 1996, Aspen Center for Physics. (Member of the organizing committee.)
- Strings '96, 15-22 July 1996, Institute for Theoretical Physics, U. C. Santa Barbara.
- Duality Symmetry in String Theory, 3-29 June 1996, Theoretical Advanced Study Institute (TASI), University of Colorado, Boulder. (Member of the organizing committee.)
- Birational Geometry, 11-14 April 1996, JAMI, The Johns Hopkins University.
- Non-Perturbative Aspects of Supersymmetric Theories, 16 January - 2 February 1996, Institute for Theoretical Physics, U. C. Santa Barbara.

- Texas Geometry and Topology Conference, 10-12 November 1995, University of Texas at Austin.
- AMS Summer Research Institute on Algebraic Geometry, 9-29 July 1995, University of California, Santa Cruz. (Member of the organizing committee.)
- Strings '95, 13-18 March 1995, University of Southern California.
- Recent Developments in Mirror Symmetry, February 1995, Oklahoma State University. (Member of the organizing committee.)

- Special Session on Quantum Algebraic Geometry, 18-19 March 1994, American Mathematical Society Southeastern Sectional Meeting, Lexington, Kentucky. (Member of the organizing committee.)

- Strings '93, 24-29 May 1993, Berkeley
- Algebraic Geometry, 1 January - 31 July 1993, MSRI

- Algebraic Geometry, 1 August - 31 December 1992, MSRI
- Algebraic Topology and Conformal Field Theory, 26-29 March 1992, JAMI, The Johns Hopkins University.

- Complex Analysis and Algebraic Geometry, 4-7 April 1991, JAMI, The Johns Hopkins University.

- Special Session on Algebraic Geometry, 24 March 1990, American Mathematical Society Southeast Section Meeting, Fayetteville, Arkansas. (Member of the organizing committee.)

- Complex Geometry and Lie Theory, 26-30 1989, Sundance, Utah. (Member of the organizing committee.)

- Scuola Matematica Interuniversitaria, 31 July - 27 August 1988, Cortona, Italy.

- AMS Summer Research Institute on Algebraic Geometry, 8-26 July 1985, Bowdoin College.

- Summer Algebraic Geometry Seminar, 11 June - 29 July 1981, Harvard University. (Member of the organizing committee.)

- Algebraic Geometry Conference, July 1977, Avignon, France.
- Algebraic Surfaces, 22-30 June 1977, Centro internazionale matematico estivo (C.I.M.E.), Cortona (Arezzo), Italy.