Ms. E. Renae Conley is the Chairman of the company. Prior to this, Ms. Conley served as the Executive Vice President, Human Resources and Administration and Chief Diversity Officer of Entergy Corporation from 2010 to 2013. Previously, she served as the Chairman, President and CEO of Entergy Louisiana and Gulf (2000 – 2010). She also held a variety of positions at PSI Energy/Cinergy Corporation, including the President of Cincinnati Gas and Electric. She is a director of PNM Resources, Inc. (NYSE: PNM), an electricity utility company.

Ms. Karen S. Haller is the company's Chief Executive Officer, President and Director. Prior to this, she worked as a lawyer in private practice. Ms. Haller has served in multiple leadership positions during her 25-year tenure with Southwest Gas, most recently serving as the Executive Vice President and Chief Legal and Administrative Officer.

Mr. Gregory J. Peterson serves as the Chief Financial Officer and the Senior Vice President of Southwest since 2012. Prior to this, he served as the Assistant Controller of the company from 2006 to 2010. Mr. Peterson started his career with Southwest in 1993 as a supervisor/accounting/technical. He served as the manager of Accounting, Senior Manager of Financial Reporting and the Assistant Controller of the company Southwest Gas. Mr. Peterson also worked in the audit division at Arthur Andersen, LLP.