Oscar and Felix on The Odd Couple (though in the final episode, Felix and Gloria remarried)
Barney Miller (was married in the first two seasons of the show, but was divorced after the third season)
Rhoda (after the third season of the show)
Willona on Good Times
When Gloria (Sally Struthers) from All In The Family got her own show "Gloria" in 1982, her and Mike were divorced.
I believe that Sally Struthers' character on Still Standing was divorced.
Weren't Ted Shackelford and Joan Van Ark's characters on Knots Landing divorced?
George Lopez's mother on The George Lopez Show.