16 Stars You Totally Forgot Were on 'Mad Men'

We finally thought that Don was able to make married life work when he said, "I do" to Megan, but in the season six premiere, fans discovered that our protagonist just couldn't resist his neighbor, Sylvia Rosen, played by Linda Cardellini. The Freaks and Geeks star continued her affair with Don off and on throughout season six and was seen sharing an elevator with Don and her husband in season seven, episode nine.

This Scream queen was only on Mad Men for one episode in season seven, but her airplane ride with Don is hard to forget. Neve Campbell played a young widow leaving California after scattering her husband's ashes at Disneyland, and she and Don struck up a conversation that made it seem like they had been friends for years. In the end, Don shocked viewers when he turned down Campbell's offer for a romantic ride home. We guess there's a first time for everything!

Before Colin Hanks was solving crimes on Fargo, he popped up on Mad Men for a few episodes of season two as Father John Gill, a priest at Peggy's family's church who knows about the child she gave up for adoption.

This Gilmore girl stepped into the world of Mad Men in season five for a three-episode arc as Beth Dawes. Although she and Pete were each involved in their own marriages, they began an affair, and Pete quickly became infatuated with the blue-eyed housewife. Unfortunately, their relationship was cut short when Beth checked into the hospital for electroshock therapy and forgot about their time together. (Fun fact: Alexis Bledel began dating her on-screen love interest, Vincent Kartheiser, after her appearance on the drama. After two years together, the couple got married in June 2014 and later welcomed a son.)

We wish all our blind dates looked as gorgeous as Anna Camp! The Pitch Perfect star first appeared on Mad Men in the season four premiere as Bethany Van Nuys, a sultry blonde who was set up on a double date with Don by Roger and Jane. Bethany always had fabulous outfits, perfect hair and a charming confidence, but unfortunately, their fling fizzled when Don became too preoccupied with work.

Before Zosia Mamet began running around New York City in HBO's Girls, the actress was running around New York City with Peggy in Mad Men. The brunette beauty played Joyce Ramsay, an open lesbian and assistant photo editor at Life magazine.

Sure you may know Larisa Oleynik from 10 Things I Hate About You or Nickelodeon's The Secret World of Alex Mack, but in the land of Mad Men, she played Ken Cosgrove's fiancée-turned-wife, Cynthia. 

Before she was helping the fastest man alive solve crimes in Central City on The Flash, Danielle Panabaker made a brief yet memorable appearance on Mad Men as Roger Sterling's mile-high fling. Daisy McCluskey flew onto the scene in season six and ended up proving helpful when it came to Sterling Cooper Draper Pryce (and Cutler Gleason & Chaough) nabbing the Chevy account.

Before she was working for creepy politicians on Scandal, Darby Stanchfield was raising her creepy son, Glen, on Mad Men. Helen Bishop and Betty Draper got into a catfight in season one when Helen confronted her neighbor for giving her son a lock of her blonde hair while babysitting.

The beloved Saved by the Bell principal took time away from Bayside to appear in season five, episode eight as an executive at Cool Whip named Phil Beachum, who met up with Don, Peggy and Ken for a special (and surely delicious!) product tasting session after hiring Sterling Cooper Draper Pryce for a new campaign.

Yet another Gilmore Girls alum made it onto Mad Men. A few years before Danny Strong stepped behind the camera as an executive producer of Empire, he played Danny Siegel, an obnoxious pipe-smoking copywriter in season four.

The former 3LW singer turned up as Lane Pryce's Playboy bunny girlfriend Toni Charles in season 4, episode 10.

Way back in Mad Men's very first episode, a wide-eyed Kristen Schaal played Nannette, one of the switchboard operators at Sterling Cooper who met Peggy on her first day on the job. But wait, there's more! See that brunette beauty behind Schaal? That's Stephanie Courtney – aka Flo from all the Progressive Insurance commercials! Courtney played Marge, another operator who appeared throughout season one.

The Cougar Town star appeared in the season seven premiere as a potential footwear client who met up with Joan for a discussion over drinks. Although he initially dismissed our fiery red-head because of her gender, he soon swallowed his pride when she came up with a brilliant advertising plan for his company.

The voice of Lisa Simpson on The Simpsons made a brief appearance as a nurse when Betty was in labor in season 3, episode 5.

Suuuunshiiiine! We bet you totally missed it in season six, episode three when Kip Pardue -- best known as Ronnie "Sunshine" Bass in Remember the Titans – guest-starred on the AMC drama. Pardue played a hotshot Heinz ketchup executive who stopped by Sterling Cooper in a snappy blue suit for an unofficial visit.