Joe Jefferson was born and raised in Englewood, Colorado. He earned his Bachelor of Science degree from Cornell University in 2002 and his Juris Doctorate from the University of Denver in 2008. Judge Jefferson was admitted to the Colorado bar in 2009 and the U.S. District Court, District of Colorado in 2011. He was the Principal Attorney of the Jefferson Legal Group, P.C. in Englewood from 2009 to 2018 and his family owns a local business, Twin Dragon Restaurant, which had proudly served the Englewood community for over 47 years until it's closure in 2023.

Judge Jefferson served on Englewood City Council from 2007 to 2018, representing Council District 1 and served as mayor from 2015 to 2018. Mayor Jefferson was the first Asian mayor and judge in Englewood history. He was elected as Englewood’s Presiding Municipal Judge in November of 2017 as the only publicly elected judge in Colorado. Judge Jefferson transitioned from mayor to presiding judge in January of 2018. He was re-elected in November 2021.

Judge Jefferson is actively involved in the local, Asian American, and legal communities. He served as President of the Colorado Municipal Judges Association from 2024 to 2025 and is a voting Board Member of the Colorado Bar Association's Board of Governors since 2024.