A native of Austin, Texas, Glenn graduated from Texas A&M University in 1986 with a Bachelor of Science degree in petroleum engineering.
Glenn joined Mobil Oil Corporation in 1986 as an operations/completions engineer and progressively held more responsible positions in the company. In 1994, he became liquefied natural gas (LNG) marketing manager in Doha, Qatar.
Following the Exxon and Mobil merger, Glenn became ExxonMobil's UK joint venture manager in London, England, in 2001. The following year he was appointed U.S. equity crude sales manager in Fairfax, Virginia.
Glenn became operations manager with the ExxonMobil Production Company in 2004, based in Houston, responsible for approximately one-third of ExxonMobil’s operated production in the United States.
In 2006, Glenn was appointed president of ExxonMobil Canada Limited and production manager for ExxonMobil Canada East, responsible for ExxonMobil's East Coast Canadian offshore business. He served as senior vice president, upstream, Imperial Oil Limited before being appointed as president of Imperial Oil Resources in 2010.
Glenn joined XTO in 2015 as senior vice president, Advisory & Support Team and International Ventures. He assumed his current role as senior vice president, Operations and International Ventures in May 2018.
Glenn and his wife, Ellen, have three children attending college.