Mario and Luigi's family
Mario and Luigi's family is the extended family of Mario and Luigi's which has been seen and referenced numerous times throughout the many games, television shows, movies and comics that make up the Mario franchise. A good majority of the family members were only ever seen or referenced on The Super Mario Bros. Super Show!, particularly during the live-action segments. These are all the known members to appear in any official form of media. It was said humorously in an interview with Shigeru Miyamoto that Mario and Luigi may possibly have a third brother.
Aunt Luigeena is an aunt of Mario and Luigi's who was only ever seen at the end of "Mama Mia Mario". Although her appearance was small, she came off as being a very bossy woman towards Mario. Given her name, there is a good chance that Luigi was named after her, much like Luigeena. Although never stated, it is likely that Aunt Luigeena is Mama Mario's sister, given their similar attitudes.
Aunt Maria is an aunt of Mario and Luigi's who has yet to make an appearance. Despite this, she has been referenced on two separate occasions. However, her personality remains a mystery. The first mention was during the events of "Crimes R Us". While looking at clouds with Mario, Luigi noted that one of them resembled their Aunt Maria.
The second mention came from Doors to Doom, in which Donkey Kong Jr.'s yell was compared to a cross of Tarzan's cry and the screech Aunt Maria makes when the Mario Bros. walk on her newly waxed floor. However, given that the Nintendo Adventure Books were produced separately from The Adventures of Super Mario Bros. 3, these two references may be a coincidence given that the name Maria is very similar to Mario.
Grandma Mario is a late grandmother of Mario and Luigi's. Her own name was stated by Mario to be his namesake. However, it is unclear as to whether she is Mario and Luigi's maternal or paternal grandmother. She came off as being somewhat stubborn.
Grandma Mario's only "appearance" was during "The Great Hereafter". Leading into the events of this segment, Mario had been having nightmares in which Grandma Mario kept scolding him, although Luigi always woke Mario up before they could finish on their own. After enlisting the help of The Old Psychic Lady with the Evil Eye Who Reads Fortunes and Knows Everything Before it Happens, Grandma Mario was able to temporarily possess Mario's body so that she could tell her grandsons to clean up their apartment.
Grandpoppy is Mario and Luigi's paternal grandfather, who was only ever seen in Nintendo Power. On page 93 of issue 7, a photograph of him can be seen hanging on a wall of Mario and Luigi's house labeled "GPoppy". Grandpoppy is similar in appearance to Mario and Luigi, except that he has a white beard and mustache and his clothes are yellow and blue.
During the segment, Luigeena and Marianne arrived at Mario Brothers Plumbing upon learning that Lyle Alzado was coming over for lunch. After flirting with Lyle for a while, Marianne sent Luigeena to look for Mario and Luigi, who had gone out to buy some groceries. After meeting up with Marianne afterwards, the two sisters returned to Mario Brothers Plumbing to announce that they were going to follow Mel Gibson home.
Mama Mario is the mother of Mario and Luigi. She has had a few minor appearances and mentions throughout the Mario series. Her most prominent appearances were during two live-action segments of The Super Mario Bros. Super Show!; "Mama Mia Mario" and "Little Marios", both of which portrayed her with a bossy demeanor and the tendency to assign her sons endless chores.
Accompanied by Luigeena, Marianne travelled to Mario Brothers Plumbing to meet up with Lyle Alzado, who was visiting Mario and Luigi for lunch. Since Mario and Luigi had left to buy groceries, Marianne and Luigeena flirted with Lyle for a while. Marianne eventually sent Luigeena to look for Mario and Luigi as an excuse to flirt with Lyle by herself, until Luigi came home and stopped her. Marianne then left to look for Luigeena and Mario, only to later return with her sister to announce that they were going to pursue Mel Gibson.
Marilyn is a wild niece of Mario and Luigi's, who is presumably related to them through her mother. She appeared during "Wild Thing", in which she invited several of her friends over to Mario Brothers Plumbing to party for a weekend without Mario and Luigi's consent. By the end of the segment, she and her friends left to party at her Uncle Troy's home in California.
Marilyn's mother is the mother of Marilyn, who was briefly mentioned by her during "Wild Thing". As Marilyn is Mario and Luigi's niece, her mother would have to be either their sister, or the wife of a third Mario brother or sister. According to her mother, Marilyn stated that she was allowed to have her friends party at Mario Brothers Plumbing.
Mario Joe and Luigi Bob
Mario Joe and Luigi Bob are brothers and the bumpkin cousins of Mario and Luigi who appeared in "Mario Hillbillies". They are identical in appearance to Mario and Luigi, but come off as being rather dim and absent-minded.
In "Mario Hillbillies", Mario Joe and Luigi Bob arrived at Mario Brothers Plumbing to go on a fishing trip with their cousins, only to learn that they had left without them due to their tardiness. Waiting around for Mario and Luigi, Mario Joe and Luigi Bob met up with Ellie Mae, a potential customer of Mario and Luigi's who ultimately befriended their cousins.
Mario's mother-in-law is mentioned by Mario in Super Mario Bros.: Favorite Mushroom Party Hits!!! during the transition between "Mockingbird" and "Mother-in-Law," saying that the listener needs to watch out for her, whom he calls a "jive Goomba", despite the fact that he is not married. Ernie K-Doe then sings "Mother-in-Law," a song about her, suggesting that he knows her.
Ojīsan and Obāsan
Papa Mario is the father of Mario and Luigi. He has made only a few minor appearances across official Mario media and as such, little about his personality is actually known.
Uncle Tony is the only confirmed uncle of Mario and Luigi's. He was briefly mentioned during "Glasnuts", and was described as a big eater by Mario, who feared that he would eat all of their pizza if he came to Mario Brothers Plumbing.
Uncle Troy is an uncle of Marilyn's who lives in California. His relationship to Mario and Luigi, if any, remains a mystery. As such, he may not even be a relative of theirs.