(written from a Production point of view)
Of Irish descent, he was Grand Marshal of the Irish Faire held in Burbank in the 1980s.
Birney was married to Meredith Baxter from 1974 to 1989. The two played husband and wife characters Bernie Steinberg and Bridget Fitzgerald Steinberg on the series Bridget Loves Bernie. Star Trek: The Original Series guest star Robert Sampson played Father Mike Fitzgerald on the series.
Birney was a guest star veteran of many popular series in from the 1960s to the 1990s, with notable guest appearances in The Streets of San Francisco, Hawaii Five-O, CBS Afternoon Playhouse (1981, with Ivonne Perez), The Love Boat, Matlock, Murder, She Wrote and Sliders (the creation of Tracy Tormé, starring Jerry O'Connell and originally including John Rhys-Davies in the cast). He also played Dr. Ben Samuels in the first season of St. Elsewhere (with Ed Begley, Jr., Norman Lloyd, Kavi Raz and Ellen Bry).
From 1995 to 1996, Birney starred in the short-lived series Live Shot. Other Star Trek stars who were also cast members include Karen Austin, Ron Canada, Jeff Yagher, Bruce McGill and Sam Anderson. Star Trek stars who guest starred include Casey Biggs, Chase Masterson, Dion Anderson, John Schuck, Lee Arenberg, Hal Landon, Jr., Cully Fredricksen and Kenneth Tigar.
Birney is also one of the few actors to have lent his talents to both the Star Trek and Star Wars franchises, having provided the voice of Anakin Skywalker in NPR's adaptation of Return of the Jedi.