Dr. Marvin Monroe is a local counselor who was for a long time considered to have passed on, until he returned, revealing to have "been very sick." Until he is seen again, dead.
Homer sold the family TV after seeing an ad for Dr. Monroe's Family Therapy Center during a boxing match at Moe's. The ad claimed "family bliss or double your money back". The Simpson family was asked to complete a series of tests, including drawing your worst fear of which everyone drew Homer, except Homer himself who drew a random doodle. Unable to reach the Simpson family, Monroe turned to the shock therapy method: the Simpsons were strapped in chairs with electrodes attached to them, and controls which they could use to shock other family members. However, it got out of hand and the whole town lost power.
Having had all his other patients leave, Monroe threw out the Simpson family, paid them the money, and told them to never tell anyone they were there. With their money doubled, they purchased a new TV.
The death of Marvin Monroe had been confirmed during 138th episode spectacular. This episode had revealed the death in the form of a question. "Which popular Simpsons characters have died in the past year?", to which the answer was " If you said Bleeding Gums Murphy and doctor Marvin Monroe you are wrong, they were never popular." He stopped appearing on TV and his business closed down. Many people in Springfield also believed him to be dead because several things had been named after him; Marvin Monroe Memorial Hospital, and a school gym. His grave is also shown, however several years later he spontaneously appeared at Marge's book signing, buying a copy of her book, The Harpooned Heart. Marge, shocked to see him, exclaimed that she hadn't seen him in years. Dr. Monroe explained that he had "been very sick".
- In Treehouse of Horror XXV, he appears to help settle the disagreements between the 1987 Simpsons and the 2014 Simpsons. When Marge asks if he's alive or dead, he responds that he's in a horrible limbo where he can pass through walls but gets stuck halfway through walls. He then gets stuck through the walls and Homer seeing his buttocks, says "And now I have to look at that every morning."
- He appeared in one of Bart's Butterfinger commercials where he shows Bart a series of inkblot tests, only to have Bart reply they all are Butterfingers, causing Dr. Monroe to say Bart is obsessed with Butterfingers and can only be cured by sharing. When it is shown that is nothing more than "give me that Butterfinger!", Bart flees Dr. Monroe's office.
- He was the boss of the Springfield Museum of Natural History in The Simpsons: Bart vs. the Space Mutants, where he causes electroshock therapy on unwilling recipients. To beat him, the player needs to jump on his head multiple times. If the player spelled Homer's name earlier, Homer will appear from paintings to drop wet blankets to neutralize the electric shocks, allowing the player to edge closer to attack, as well as stun Monroe if he is in close proximity.
- The inspiration for Marvin Monroe came from Robert Allan Monroe.
- His name has a similar spelling and pronunciation from deceased actress/model Marilyn Monroe.
- On the audio commentary for the episode Some Enchanted Evening, David Silverman discloses that the reason the character was named Marvin Monroe was due to the original idea that it was going to be revealed that his real name was actually Marilyn Monroe, which as a result, made him become a therapist, because he was really "hung up" on that. 
- "There's No Disgrace Like Home"
- "The Call of the Simpsons"
- "Some Enchanted Evening"
- "Itchy & Scratchy & Marge"
- "Who Shot Mr. Burns? (Part Two)"
- "Bye Bye Nerdie"
- "Alone Again, Natura-Diddily"
- "Diatribe of a Mad Housewife"
- Silverman, David (2001). The Simpsons season 1 DVD commentary for the episode "Some Enchanted Evening"(DVD).
- Jean, Al 2001 Commentary for "Some Enchanted Evening," in The Simpsons: The Complete First Season.
- Groening, Matt 2003 Commentary for "Treehouse of Horror II," in The Simpsons: The Complete Third Season.