Diane Cullinan Oberhelman
Chairman/Founding Partner
Diane is the Founding Partner of Cullinan Properties, based in Peoria, Illinois, with offices in Chicago, Illinois and St. Louis, Missouri. Diane founded Cullinan Properties in 1988 after being in the real estate business since 1981, and is currently the Chairman. Today Cullinan Properties, Ltd. has evolved into a premier provider of real estate development & acquisitions focusing on commercial and mixed-use developments including retail, medical, office use, and multi-family nationwide.  Cullinan Properties has developed over $1 billion in projects and has had a strategy that has successfully executed and delivered in recent turbulent economic times. Diane is married to Doug Oberhelman and has four grown children: Kathleen Cullinan Brill, Maureen Cullinan Bennett, Alison Cullinan Unkovich, and Allen Cullinan. Doug is the recently retired Chairman and CEO of Caterpillar Inc. They also have ten grandchildren: Austin Brill, Michael Bennett, Hudson Brill, Avery Bennett, Duane Douglas Cullinan, Mary Michael Cullinan, Duke Unkovich, Cameron Cullinan, Luke Allen Bennett and Tilley Nadine Unkovich. Her leadership and board affiliations have included:
  • Two-term Member, Federal Reserve Advisory Council of Chicago
  • Chairman, Illinois Development Finance Authority
  • Member, Illinois Economic Development Board
  • Member, Ducks Unlimited Board of Directors
  • Member, Kids Konnected Board of Directors
  • Member, Multi-Ad Services, Inc. Board of Directors
  • Member, Peoria Civic Center Authority Board
  • Member, Susan G. Komen Board of Directors
  • Co-chair, Salvation Army Tree of Lights Campaign 2004
  • Member, OSF Foundation Board
Diane’s awards and recognitions include being honored as the 40 Leaders Under Forty Alumnus of the Year in 2015; induction into Junior Achievement’s Central Illinois Business Hall of Fame in 2006; the Boy Scout Distinguished Citizen of the Year Award for Central Illinois in 2005; the Central Illinois Volunteer of the Year Award in 2005; being named one of the 25 Women In Leadership in 2002; and receiving the Illinois Chamber of Commerce Athena Award in 1996.