Jensen Buchanan was born in Montgomery, Alabama on July 18, 1962 and raised in Neenah, Wisconsin. She developed a love of music as a child, and after graduating high school she attended Boston University to major in voice with a concentration in opera. She appeared in several musical productions while studying at the Boston University Theater Institute, after which she moved to New York to perform with the Light Opera of Manhattan.

In 1987 Jensen landed her first daytime role as Sarah Gordon on One Life to Live. Then in 1991 she got the role of twin sisters Vicky Hudson and Marley Love on the NBC soap opera Another World. She remained on Another World until its cancellation in 1999. During her years there, she married Gray O'Brien and the couple had two sons, Conor (born April 1994) and Angus (born February 1996). She was nominated for two Daytime Emmy Awards for Outstanding Lead Actress (1996 and 1997). After Another World's cancellation, Jensen appeared on As the World Turns and General Hospital before retiring from acting to raise her two boys. In 2003 Jensen married Sam Gores. The couple divorced in 2013.

In 2015 Jensen returned to daytime in the recurring role of Elise Moxley in The Young and the Restless.