- The second oldest in a family of eight children.
- Studied acting at the Stella Adler Conservatory while attending NYU.
- Made her TV-series debut in 1975 as Mary Ryan in the daytime soap Ryan's Hope.
- Debuted on prime-time TV in an episode of Columbo as the Lieutenant's crimefighting wife, Kate; starred in the short-lived spin-off Mrs. Columbo.
- Debuted on Broadway in a 1994 production of Black Comedy.
- Was initially rejected for the role of Capt. Janeway on Star Trek: Voyager, but landed the part when Genevieve Bujold backed out after only two days; became the first woman to head a series in the Star Trek franchise.
- An active supporter of the Alzheimer's Association; her mother, who died in 2006, endured a long battled with the disease.
- 2014, Emmy — Outstanding Supporting Actress in a Comedy Series: Nominee
- 1980, Golden Globe — Best Performance by an Actress in a Television Series - Drama: Nominee
- 2014, Critics' Choice Television Awards — Best Supporting Actress in a Comedy Series: Winner
- 2014, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Comedy Series: Winner
- 2015, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Comedy Series: Winner
- Jenny — Sister
- Robert Harry Egan — Ex-husband
- Alexander James Egan — Son
- Joe Mulgrew — Brother
- Laura — Sister
- Sam Mulgrew — Brother
- Ian Thomas Egan — Son
- Eleanor — Stepdaughter
- Danielle — Daughter
- Thomas James Mulgrew — Father
- Tom Mulgrew — Brother
- Joan Virginia Mulgrew — Mother
- Tim Hagan — Husband
- Marie — Stepdaughter
- Attended Clarke College, Dubuque, IA; New York University, New York, NY
Season 7, Episode 21
- Birth Name: Katherine Kiernan Mulgrew
- Birth Place: Dubuque, IA
- Birthday: April 29, 1955, Taurus
- Profession: Actor