Janel Moloney (born October 3, 1969) is an American actress, best known for her role as Donna Moss on The West Wing.

Born in 1969, in Woodland Hills, California, Moloney is the niece of Christine Ebersole, and attended an actors' training program at SUNY Purchase. Her early work included television guest roles on ER, Sports Night and Murder, She Wrote.

In 1999, Moloney became a recurring guest star on The West Wing as "Donnatella Moss", assistant to Deputy White House Chief of Staff Josh Lyman (Bradley Whitford). Intended only to be a guest star, like the many other recurring assistants on the show, the cast and creator Aaron Sorkin - and the fans - quickly noticed the chemistry between Donna and the rest of the cast, particularly Josh. Beginning with the second season premiere, Moloney was listed in the main credits. Her unfulfilled relationship with Josh became a favorite of shippers, as both of the characters went through other relationships. After Sorkin left the series following its fourth season, a more character-based approach was implemented by new head John Wells, and the Josh-Donna relationship was again suggested after she was injured in a bombing in Gaza. The show has been picked up for a seventh season (2005 - 2006) which will see the end of the Bartlet administration. It is unknown whether Moloney will stay with the show after this.

Moloney has also appeared in the TV film Bang, Bang, You're Dead with Thomas Cavanagh and Randy Harrison, and played the part of Amber Frey in Amber Frey: Witness for the Prosecution, broadcast on CBS May 25, 2005.

She currently lives across the street from The West Wing co-star Allison Janney.

During the 2004 U.S. Presidential campaign, Moloney was an active supporter of John Kerry and made public appearances on behalf of his campaign.