The attractive blonde found a better range of roles on the small screen. While still in her ingenue stage, Geeson spent two years (1965-67) as the teenaged daughter in a family that moved from London to the countryside in the British drama series "The Newcomers" and essayed the role of Lucy Honeychurch in a BBC 1973 adaptation of "A Room with a View". As she matured, Geeson performed in a range of comic and dramatic roles, including a role as a leader on a planet ruled by women where men were slaves in "Star Maidens" (syndicated, 1977-78). She was Emmy-nominated for a guest appearance on "Archie Bunker's Place" (CBS, 1981), and often guest-starred on primetime series, including "Murder, She Wrote", "The A-Team" (NBC, 1986), "MacGyver (ABC, 1988) and "Star Trek: Voyager" (UPN, 1995), the latter in the recurring role of Sandrine. Geeson achieved a more lasting recurring role on the highly regarded and popular Helen Hunt-Paul Reiser comedy series "Mad About You" (NBC, 1992- ), playing their snooty British neighbor Helen. Other notable credits include "Poldark II" and "Danger U.X.B.", both seen in the USA on PBS's "Masterpiece Theatre". She came full-circle in 1996 when she reprised the role of Pamela in the CBS TV-movie "To Sir With Love II", making a cameo appearance in a scene in which a retiring Sidney Poitier is being honored.
Geeson, whose younger sister Sally is also an actress, was formerly married actor-director Kristoffer Tabori, with whom she appeared in the Off-Broadway play "The Common Pursuit".