Sean P. Thorstenson, CPA

Sean Thorstenson, CPA, MST

Tax and Advisory Services Partner

714-978-1300 |

Sean joined White Nelson Diehl Evans LLP in January 1996 and currently serves as a Tax and Advisory Services Partner. His diverse background includes experience with corporate and partnership taxation. He also provides compliance and planning services for high net-worth individuals, including estate and trust planning. Although he works with all privately-held businesses, he has developed specialized skills in the manufacturing, distribution, retail & retail fuel outlets, professional services and real estate industries.

A resident of San Clemente, Sean and his wife, Andrea, have three children. He enjoys spending time with his family, taking road trips, camping, playing golf and going to the beach.


Technical and Service Expertise:

  • Corporate and partnership taxation
  • Tax compliance and planning for high net-worth individuals

Industry Expertise:

  • Manufacturing
  • Distribution
  • Real Estate
  • Retail/Retail Fuel Outlets
  • Professional Service Firms
  • Construction & Contracting

Professional Affiliations:

  • CalCPA

Community Involvement:

  • Former Finance Chair, Recovery Resource Council
  • CSUF Executive Golf Committee Member


Chapman University

  • Bachelor of Science, Accounting

California State University, Fullerton

  • Master of Science, Taxation