Shirley Baum is vice president of law for Pinnacle West Capital Corporation and its primary subsidiary, Arizona Public Service Company (APS), Arizona’s largest energy company. The companies are headquartered in Phoenix. 

Since 2019, Baum has served as deputy general counsel with oversight of various legal functions, including corporate/commercial, regulatory, litigation, environmental, nuclear, and labor and employment practice groups. As vice president of law, she assumed additional responsibility for law department operations and oversight of the external firms that bring additional expertise to the department.

Baum joined Pinnacle West in 2007 as a senior attorney and became associate general counsel in 2010. Prior to joining Pinnacle West, she was the assistant general counsel for Mobility Electronics, Inc., an associate attorney with Snell & Wilmer, LLP, and a tax consultant for Deloitte.
 
Baum is a Certified Public Accountant and a member of the State Bar of Arizona and the Arizona Board of Accountancy. She graduated from the University of Notre Dame and earned a law degree from the Arizona State University College of Law. Baum is currently serving on the Board of the Sandra Day O’Connor Institute for American Democracy and the Board of the McDowell Sonoran Conservancy.