Monica Johnson (February 21, 1946 – November 1, 2010) was an American screenwriter whose film credits included Mother, Lost in America, Modern Romance, Jekyll and Hyde... Together Again and The Muse. Her television credits included The Mary Tyler Moore Show, Laverne & Shirley and It's Garry Shandling's Show. She was a frequent collaborator with Albert Brooks.

Johnson was born Monica Lenore Belson in 1946 in Colorado but was raised in El Centro, California, and spent her early years in medical and dental assistants’ school.

Her brother, Jerry Belson, an Emmy Award-winning screenwriter and film producer, hired her to type scripts for the TV series The Odd Couple around 1972; noticing that his sister added jokes to the scripts, which met with the producers' approval, he suggested that she partner with Marilyn Suzanne Miller to form a writing team. Initially working under her married name Monica Mcgowan in 1973, she and Miller wrote three scripts for The Mary Tyler Moore Show. For the second script, having remarried, she was credited as Monica Mcgowan Johnson. By the time of the third script in 1974, she was credited as Monica Johnson, the professional name she used for the rest of her career.

Miller and Johnson broke up as a writing team in 1974; Miller became one of the original writers for Saturday Night Live in 1975.

Johnson later became a writer/producer on Laverne & Shirley and worked on a couple of TV movies, then began her long-term screenwriting collaboration with Albert Brooks in 1979 with the film Real Life. The two co-wrote five more of Brooks' films over the following two decades.

Johnson wrote the book Penny Saver (unpublished) and the movie Marrying for Money (unproduced) and began doing artwork.

Johnson, a resident of Palm Springs, California, died of esophageal cancer at Cedars-Sinai Medical Center in Los Angeles on November 1, 2010, aged 64. She was survived by her seventh husband, Charles Lohr; a daughter, Heidi Johnson; and a brother, Gordon Belson.