From Homestar Runner Wiki
At the Flashforward 2006 Seattle public appearance, The Brothers Chaps revealed that emails they receive asking about the characters' parents are one of the groups of emails that are virtually certain not to be answered.
- Super NES and Theme Song Video — One of the lyrics to the song is "Homestar Runner, mom and dad".
- Homestar's Yearbook — Homestar says, "Sign my yearbook! But don't use any swears, because... my mom reads it."
- Senorial Day — As part of his role in Bubs's commercial, Homestar acts like Bubs is his father and dresses up as such.
- Email shapeshifter — Homestar doesn't want to talk to the "scarf from grandma", possibly implying that he thought that it was from his own grandmother.
- 79 Seconds Left — Homestar refers to himself as the Cow Leg's daddy.
- Fan Costumes '09 — Homestar seems to believe that Strong Bad is his kid, after seeing a picture that shows a man dressed as Homestar, a woman dressed as Marzipan, and a small child dressed as Strong Bad.
- Homestarloween Party — Strong Bad admits that his mother helped him with his costume.
- The Secrets That I Keep — The birthday card that Strong Bad gave Strong Sad has "mom says I have to make you this kard " written in it.
- Email 50 emails (DVD Commentary) — After wondering why Strong Bad has a fondue pot, Matt Chapman suggests that it's his mom's. In mock fan obsession, he excitedly asks, "Oh man, what is his mom parent..ing like... today?"
- Email cheatday — The Cheat reads one email asking what The Brothers Strong's parents look like, but he responds by threatening to gnaw the email sender's face off (which apparently is his response to every email).
- The Screen Savers Interview - 24 Jan 2005 — Joe from Pomona, California asks Strong Bad why we never get to see his parents. The question angers Strong Bad. Strong Bad later warns the host Kevin Pereira to never talk about his mother.
- Email the facts — Strong Bad tells Strong Mad that "Mom says to keep it down 'cause baby Strong Sad's sleeping."
- Email the chair — After ripping his mask off, Strong Bad holds up an alleged picture of his parents, although it is obscured by the new high-backed chair. However, using a Flash decompiler reveals that the picture is blank except for the message "nice try dodongo".
- Email mini-golf — When the Drive-Thru Whale says, "Pour gravel on your stump please, ma'am," Strong Bad asks, "Did you just tell my mom to pour gravel on her stump?"
- Email slumber party — Strong Bad mentions that Strong Sad used to get picked up early from the slumber parties they used to have in their own basement because he missed their mother.
- Email environment — Strong Bad is seen typing up a list of mother-approved synonyms of "butt".
- Email buried — Strong Bad believes his parents are aliens.
- Email shapeshifter — Strong Bad mentions having the power to turn into "presents your grandma's knitted for you", and later transforms into a scarf from by his grandmother, whom he refers to as "G-moms".
- Email rated — Strong Bad admits that Coach Z kind of looks like his mother.
- Email specially marked — Strong Bad tells cereals that require a parent to write a check for the shipping and handling to "leave [his] mom out of this!"
- Homestar Ruiner — Strong Bad tries to get Strong Sad to get out of his room by pretending to be their mother. Strong Sad replies "You're not even my real mom!"
- Dangeresque 3: The Criminal Projective — Senor Cardgage acts as Dadgeresque (Dangeresque's dad). Dangeresque also admits the stickanee flower he was showing to Cutesy Buttons was "for [his] mom".
- Dangeresque Roomisode 1: Behind the Dangerdesque — Dangeresque mentions that his grandma used to air her whoozit out.
- Compy Catalog — The Decemberween present in Strong Bad's imagination is given by either one of his parents.
- Later That Night... — Strong Bad tells Homestar "You leave my father out of this!"
 Other Main Characters
- Old Characters Page — The King of Town's bio states that he is Marzipan's father. This is the only such concrete reference on the site, and The Brothers Chaps have since reported in interviews (such as the Club Aquatica interview) that this was an idea they had early in the site's development but have since abandoned. However, it was revisited in Marzipan's Answering Machine Version 17.2.
- Pom Pom, Too — Pom Pom's parents are seen in a photo.
- Email interview — While demonstrating what an interview with Homsar would be like, Strong Bad as a Homsar puppet says "I was raised by a cup of coffee!"
- Email pom pom — Strong Bad writes a letter to Pom Pom's parents, addressing them as "General and Fraulein Pom Pom".
- Homestar Presents: Presents — Coach Z pretends to be talking to his parents on a disconnected phone.
- Email garage sale — Coach Z claims that he is a mother.
- Halloween Potion-ma-jig — Coach Z thinks Strong Bad is dressed up as Coach Z's hot mom.
- Weclome Back — Strong Bad says, to a gathering of main characters, but to no one in particular, "What am I, your dad?"
- Fan Costumes '06 — Strong Bad thinks one of the costumes looks like The Cheat's hot mom.
- He later mentions The Cheat's hot mom in Homestar Ruiner.
- Email fan club — Homsar states that he is the "son of a Chipwich", and an Easter egg shows a picture of his "parents".
- Email pet show — The King of Town berates the As Seen on TV Low-Fat Cooking Device by saying he's not its real father.
- A Death-Defying Decemberween — Homestar and Marzipan go to Marzipan's parents' house at the end of the toon. Marzipan's mother, "Mrs. Marzipan", is apparently frequently divorced. Her current husband, Seth, is a philosophy professor.
- Email independent — Strong Bad mentions Pom Pom's father, who apparently owns his own studio.
- Fan Costumes '09 — Strong Bad implies that Homestar and Marzipan's son would be Homsar.
- I Killed Pom Pom — The King of Town says to The Poopsmith, "Stop acting like my dad!"
 Minor Characters
- Homestarloween Party — The Visor Robot's brain is said to have belonged to the Sad Kids' father.
- Email army — Homestar tells Mrs. Bennedetto that her son, Frank, died in battle.
- The Li'l Brudder Show — Li'l Brudder's parents are shown to be a unicycle and a dog.
- Let us give TANKS! — Reynold says that he is going to his parents' house for Thanksgiving.
- Email hygiene — Gene's "young and hot" mother buys his clothes, and lets him take the boat out when she has a 'grown-up' headache.
- Limozeen Live! (practice) — The corner of the advertisement reads, "Watch us practicing in our
parents'basement". Also, a pop-up during the video reads, "We use acoustics and no drums when we practice so our mom can talk to her friend Gerdith" (the word "mom" gets replaced with "landlord" after a few seconds).
- Email magic trick — The magician in the book apologizes to his mother after shoving a squirrel into his pants. Also, in an Easter egg, D n' D Greg tells Coach Z, "I'm gonna have to ask you to leave my parent's basement now."
- 2 Part Episode: Part 1 — At least one of the Blue Laser Minions calls Blue Laser Commander "Dad", which he apparently hates.
 Teen Girl Squad
- Teen Girl Squad Issue 4 — Cheerleader has "cool parents!".
- Teen Girl Squad Issue 5 — Olda boy 2 says "I miss my mom!"
- Teen Girl Squad Issue 6 — What's Her Face "wants a new stepdad!".
- Teen Girl Squad Issue 8 — So and So's stepmother is seen, referred to as Mrs. So and Soerson. The girls practice for the battle of the bands in Mrs. So and So-erson's closet. She tells the girls to "Shut your yaps!". Afterwards, she pours ranch dressing on The Ugly One.
- Teen Girl Squad Issue 10 and Teen Girl Squad Issue 15 — The Ugly One's father, Manolios Ugly One, is seen.
- Teen Girl Squad Issue 13 — Tompkins' mother, Momkins, is seen. At the end, Timkins points at one of the policemen and says, "You're not my real father!"
- Homestar Ruiner — Giving the car to a girl will make her mention her "real dad".
- Baddest of the Bands — What's Her Face accuses Limozeen of being older than both her fathers.
- Decomposing Pumpkins — Brainkrieg plays in their lead singer's mother's garage. The "plump kid" whose "mom did not give us good candy on Halloween" is revealed at the end to be their drummer.
 Other Relatives
- Email Family Resemblence — Strong Bad tries to envision Pom Pom's family "resembling" him (at least, to the same extent that Strong Bad's brothers resemble himself).
- Email secret recipes — Strong Bad and Homestar reference several (possibly and/or definitely made-up) relatives: Strong Bad's "Great Uncle Pawdabber", his "Crazy Aunt Eulatherm", his mystifying "Poopaw", and Homestar's (definitely non-existent) "Stupid Uncle Egg".
- Email bedtime story — Strong Bad says that he is The Cheat's "Dadbysitter".
- Email candy product — One line of Strong Bad's jingle says "Livin' in the gutter with grandma".
- Email alternate universe — Senor Cardgage wants to adopt Strong Bad, but Strong Bad disappears before he can do so.
- Happy Hallow-day — Homestar Runner reminisces about pushing his grandma on a wheelchair through "the old town". This (most likely false) memory is stimulated by Coach Z's unrealistic broken-wheelchair-on-cobblestone sound effects.
- Email looking old — Strong Sad allegedly mistakes Strong Bad for their great-grandmother after he gets a "lace-lift".
- Email more armies — The On Point Kings' brochure mentions The Cheat's sister as one of their clients.
- Email slumber party — Bubs mentions his cousins Louis and Harold, who are both deceased.
- Happy Dethemberween — Marzipan reminds Strong Bad that The Decemberween Thnikkaman is not better than her "hot cousin" Debra.
- Homestar Ruiner — When you use the car on any girl in the Teen Girl Squad minigame, she says that her father bought it.
- Strong Badia the Free — Homsar performs an ancient ceremony his Uncle Chet taught.
- Page Load Error — Part of the error message says "Did you make a mistake when typing the domain? Did you grandma?"
- Most in the Graveyard — After Bubs clears up that he and Coach Z are only distant relatives at the most, Coach Z comments, "So your sister and I can..." before Bubs proceeds to punch him. An outtake later featured as the Quote of the Week had Bubs saying, "Stay away from my sister!"
- Hooked on Decemberween — Brainkrieg's song "If I Don't Get Videogames..." mentions "Crazy Uncle Edgar".
- Fish Eye Lens — Strong Bad says that with a fish eye lens, "your mom" would say, "Those are some exceptionally smooth moves!"
- The House That Gave Sucky Tricks — Strong Bad decides to use a Horrible Painting of Somebody's Dad to scare people who enter St. Cadaverstump's Morgue-tuary.
- Marzipan's Answering Machine Version 17.2 — Homestar Runner mentions that Marzipan has a sister.