Charlie's real-life dad played Rose's father (Season 3, Episode 7), while older brother Emilio dropped by as an old drinking buddy who croaked on Charlie's deck (Season 6, Episode 11).
Sheen's then-wife and Kutcher's current wife both put in appearances. Richards recurred as Charlie's ex-girlfriend Lisa (Season 1, Episode 10); Kunis played free-spirit Vivian (Season 11, Episode 19).
Before Mom, Janney guest-starred as Alan's online date Beverly (Season 4, Episode 15). Six years later, Pressly recurred as Jake's much older girlfriend Tammy (Season 10, Episode 15).
Cyrus recurred as Jake's love interest Missy (Season 10, Episode 4). Former Hannah Montana BFF-turned-Young Sheldon star Osment played Tammy's daughter Ashley (Season 10, Episode 20).
The fellow Disney Channel grad guest-starred as Walden's Instagram-obsessed date Stacey (Season 10, Episode 23).
Henner guest-starred as Stacey's grandmother Linda (Season 10, Episode 23), while her Taxi costar played Melissa's mom Shelly (Season 6, Episode 12).
Before she was Young Sheldon's Meemaw, the Designing Women vet played Judith's alcoholic mother Lenore (Season 7, Episode 3).
Before she was cast as Melissa McCarthy's TV sister on Mike & Molly, the future American Housewife star recurred as stripper/part-time masseuse Betsy (Season 7, Episode 16).
The former Lois Lane guest-starred as Judith's sister Liz (Season 1, Episode 19), while the OG Wonder Woman played herself… and had a threesome with Charlie's daughter Jenny and Walden's mother Robin (Season 11, Episode 6).
Elfman initially played Frankie, Alan's first love interest following his divorce from Judith (Season 1, Episode 15). Eight years later, she returned as Dharma, opposite Gibson's Greg, who were prospective buyers of Charlie's Malibu beach house (Season 9, Episode 1).
Before she joined Criminal Minds, Gibson's longtime costar guest-starred as Alan's high-school classmate Jamie Eckleberry (Season 2, Episode 12).
Seven years before joining NCIS: Los Angeles, O'Donnell appeared as Charlie's ex-girlfriend Jill—err, Bill (Season 1, Episode 18).
The CBS comedy hosted a pair of Spin City reunions, with Locklear showing up as Alan's divorce attorney (Season 1, Episode 21) and Kind showing up as Charlie's agent Artie (Season 5, Episode 8).
Wagner initially recurred as Evelyn's beau Teddy (Season 4, Episode 24), while McCarthy initially played his daughter Courtney (Season 5, Episode 9). But during a crossover with CSI — yes, there was a crossover with CSI — it was revealed that Teddy and Courtney were grifters Nathan Krunk and Sylvia Fishman.
TV's Hercules played Kandi's dad Andy (Season 3, Episode 20), while the erstwhile (and superior) Xena: Warrior Princess guest-starred as Pamela, the wife of a closeted ad exec (Season 2, Episode 18).
Fox played Berta's granddaughter Prudence (Season 1, Episode 12); Manheim played Berta's sister Daisy (Season 2, Episode 7); and Rue played Berta's daughter Naomi (Season 4, Episode 7).
Prior to , Brown appeared as Mandy, an attendee at Judith’s women’s support group (Season 1, Episode 23). The following year, Jeong had a non-speaking role as “Male Nurse” (Season 2, Episode 17).
Penn, Costello and Stanton cameoed as members of an exclusive men’s support group hosted by Charlie (Season 2, Episode 1).
Three years before Alan gave the eulogy at Charlie’s funeral, Jones gave the eulogy when Charlie dreamt of his eventual demise (Season 6, Episode 11).
The host revealed his bacon bits (Season 11, Episode 7), then returned for a swingers’ party. (Season 11 was , you guys.)
’ Mrs. C turned up at the same swingers’ party as Probst and courted a down-on-his-luck Zippy (Season 11, Episode 12).
Six years before she was cast as Charlie’s fiancée Chelsea, Taylor guest-starred as Suzanne, a woman who takes an interest in Charlie while he’s out grocery shopping with Jake (Season 1, Episode 1).
Five years before she made her debut as Walden’s ex-wife Bridget, Greer guest-starred as Herb’s sister Myra (Season 4, Episode 19).
Six years before she was introduced as Walden’s girlfriend Kate, D’Orsay appeared as Robin, a younger woman with an even stronger libido than Charlie (Season 4, Episode 16).
