Main cast (Mary Hartman) and
Greg Mullavey (Tom) in a publicity still •
Louise Lasser as Mary Shumway Hartman, the title character, an
Ohio housewife. •
Greg Mullavey as Tom Hartman, Mary's unfaithful husband and Heather's father. Works on an
assembly line. •
Mary Kay Place as Loretta Haggers, Mary's best friend and neighbor, and aspiring
country singer. •
Graham Jarvis as Charlie "Baby Boy" Haggers, Loretta's much older husband and Tom Hartman's best friend and coworker. •
Dody Goodman as Martha Shumway, Mary's often daft mother known for talking to her plants. •
Debralee Scott as Cathy Lorraine Shumway, Mary's
vampish sister. •
Victor Kilian as Grandpa Raymond Larkin, Martha's father, who was revealed in the pilot episode to be the "Fernwood Flasher." •
Philip Bruns (and for a few episodes after the show was rebranded as
Forever Fernwood,
Tab Hunter) as George Shumway, Martha's husband and Mary and Cathy's father. He worked at an automobile assembly plant along with Tom and Charlie. •
Claudia Lamb as Heather Hartman, Tom and Mary's troubled adolescent daughter.
Supporting cast • Samantha Harper as Roberta Wolashek, Grandpa Larkin's young social worker, who falls in love with him. •
Salome Jens as Mae Olinski, Tom's Amazonian co-worker at the assembly plant and the payroll officer, with whom he had an affair. •
Bruce Solomon as Sgt. Dennis Foley, a Fernwood police officer who liked Mary and with whom she eventually ran off. (See
Forever Fernwood, below.) •
Norman Alden as Coach Leroy Fedders, Tom's former high school coach. He died drowning in Mary's chicken soup. •
Reva Rose as Blanche Fedders, Coach Fedders' constantly protesting and militant wife. •
Martin Mull as hateful wife-beater Garth Gimble, who died by being impaled by a star on an aluminum Christmas tree. Mull later played Garth's twin brother, Barth Gimble, a more overtly comic character who showed up in Fernwood to lay low after some sort of trouble in Miami. After playing Barth on
MHMH for a handful of episodes, Barth was spun off to on his own series, the talk show parody
Fernwood 2 Night (which later evolved into
America 2-Night). •
Susan Browning as Garth's wife, Pat, the target of his abuse. •
Sparky Marcus as Jimmy Joe Jeeter, child
evangelist, who died when a TV set he was watching fell into the bathtub, electrocuting him. •
Dabney Coleman as Merle Jeeter, Fernwood's slightly devious mayor and Jimmy Joe's father. •
Marian Mercer as Wanda Rittenhouse Jeeter, a widow of a city commissioner and a former sanitarium mate of Mary's, who became Jeeter's second wife while also carrying on a relationship with their maid, Lila. •
Gloria DeHaven as
CB radio aficionado Annie "Tippy-toes" Wylie, who also had an affair with Tom Hartman. •
Orson Bean as Reverend Brim, one of Fernwood's clergymen, mainly in
Forever Fernwood. •
George Furth as Reverend Harold Standfast, who helped Mary through the Davey Jessup hostage crisis. He had to swear on a stack of Bibles to have Mary released, but only did so after being threatened with the exposure of an extramarital affair he had with Florence Baedecker, the choir mistress of his church. •
Mary Carver as Christine Standfast, Reverend Standfast's wife, who knew all about her husband's extramarital affair. •
Shelley Fabares as Eleanor Major, a woman who Tom Hartman fell in love with after Mary had left him and Heather for Sgt. Foley. •
Judith Kahan as Penny Major, Eleanor's sister, who married Tom Hartman in the series finale. •
Will Seltzer as Davey Jessup, the murderer of the Lombardi family, their two goats and eight chickens, who held Mary and Sgt. Foley hostage. Before that, he had also held Mary's daughter Heather and her best friend, Trudy Weathersby, hostage. •
Doris Roberts as Dorelda Doremus, a
faith healer. •
Michael Lembeck as Clete Meizenheimer, television news reporter for Fernwood's local television station. •
Archie Hahn as Harold Clemens, a reporter for the town's newspaper, the
Fernwood Courier. •
Vivian Blaine as Betty McCullough, Mary's fortune teller neighbor who was helping her son and his male partner hide their true relationship. •
Sid Haig as Texas, a production worker at the automobile plant in Fernwood. •
Ed Begley Jr. as Steve, a deaf man who dated Cathy. •
John Heffernan as Chester Markham. •
Laurence Haddon as Ed McCullough • Beeson Carroll as Howard McCullough •
Hugh Gillin as Tiny ==History and production==