Successful lawyer, doting father, avid baseball fan, amateur magician. Played by James Broderick.
Kate Lawrence (née Skinner)
The portly, all-wise mother; resolver of all conflicts, healer of all wounds. Eventually got tired of just being a housewife, and went back to college for a music degree, then got a teaching job at her daughter's high school. Played by Sada Thompson (Emmy winner, 1978).
Nancy Lawrence Maitland
Eldest daughter, aspiring lawyer, soon-divorced mother of a young son. Through the miracle of re-casting, turned from a shy brunette into a glamorous blonde. Played by Elayne Heilveil (1976), Meredith Baxter Birney (1976-80).
High-school drop-out, photographer, wannabe writer, periodically moonlighting as a contestant screener for a TV show called "The Dame Game." Played by Gary Frank.
Letitia ("Buddy") Lawrence
The all-American girl next door; naive at times, mature beyond her years at others. Affectionately called "Peaches" by Willie, "Tizzylish" by Kate. Played by Kristy McNichol (Emmy winner, 1977, 1979).
Andrea ("Annie") Cooper Lawrence
Wunderkind adopted by the Lawrences after her parents were killed in a car accident. Played by Quinn Cummings (1978-80).
Nancy's ex-husband; likeable, but reckless. Played by John Rubinstein, who also wrote the theme song.
Drowned in a boating accident five years before the show began, traumatizing his parents and siblings for life. (Or, at least, for one episode, as he was hardly ever mentioned again.)
Timmy (Timothy Charles) Maitland
Nancy and Jeff's son, named after the other Timmy. Played by Michael David Schackelford.
Buddy's best friend, and the answer to the trivia question, "What did Buddy Lawrence and Kevin Arnold have in common?" Played by Louise Foley.
Willie's one-time girlfriend, who, when they first met, was carrying some other guy's kid. Played by Season Hubley.
Alexandra ("Alex," "Big Al") Friel
Part-owner of a bakery (called "Your Just Desserts") where Buddy worked; Willie's girlfriend, for a while. Played by Jane Alice Brandon.
Willie's wife, for a brief period. Played by Brooke Adams.
Another of Willie's girlfriends, played by Devon Ericson.
Buddy's first boyfriend, played by Willie Aames.
Buddy's second boyfriend, played by Leif Garrett.
Nancy's former professor and one-time boyfriend, played by David Hedison.
Kate's best friend, who always asked her to contribute to one charity or another. Played by Priscilla Morrill.
The nosy, do-nothing housekeeper, played by Mary Grace Canfield, et al.