Ness played High School hockey at Roseau High School in Roseau, Minnesota, and in 2008 he received the Minnesota Mr. Hockey award as the most outstanding senior high school hockey player in the state of Minnesota.[2] In an effort to be able to play collegiate hockey one year earlier than projected, Ness accelerated his course load during his junior year of high school in order to graduate early. A combination of 8 classes at school as well as 3.5 credits online, however, did not stop him from leading his team to a fourth-place finish at the 2008 2A State Tournament.[3] Ness then attended the University of Minnesota, where he played three seasons of NCAA Division I college hockey with the Minnesota Golden Gophers.
On July 1, 2015, Ness left the Islanders organization as a free agent and signed a one-year, two-way contract with the Washington Capitals.[6] He later re-signed with the Capitals on May 16, 2018, to another one-year two-way contract.[7]
The Capitals called Ness up from Hershey on November 8, 2018, together with fellow defenceman Jonas Siegenthaler, to be available to play against the Columbus Blue Jackets the next night at home in his first NHL game.[8] Veteran Caps defencemen Brooks Orpik (injured reserve) and John Carlson (day-to-day) were both unavailable to play.[9]
After four seasons within the Capitals organization, Ness left as a free agent to sign a two-year, two-way contract with the Arizona Coyotes on July 1, 2019.[10]
Having left the Coyotes organization as a free agent, Ness was signed to a one-year AHL contract with the Providence Bruins on September 30, 2021, and was invited to the Boston Bruins training camp on a professional try-out.[11] He was later signed to an AHL contract with affiliate, the Providence Bruins.
On July 5, 2022, Ness as a free agent, opted to continue his career in the AHL by returning to his former club, the Hershey Bears, on July 5, 2022.[12]
On October 23, 2024, Ness was promoted to captain of the Hershey Bears, after Dylan McIlrath went up to Washington.[13]
^Rand, Michael. "BOYS' HOCKEY NOTES; Aaron Ness of Roseau wins Mr. Hockey award." Star Tribune [Minneapolis, MN] 10 Mar. 2008: 10C.Business Insights: Essentials. Web. 11 Oct. 2015.
^Spiros, Dean. "Taking the fast track to stardom; Acceleration is at the forefront for Roseau's Aaron Ness, be it on the ice or in the classroom."Star Tribune [Minneapolis, MN] 8 Feb. 2008: 01C. Business Insights: Essentials. Web. 11 Oct. 2015.