How I Met Your Mother is a nine-season long show which has lots of Shout Outs. Alas, the sheer number of actors involved with the show (main cast, recurring or one-offs) makes it almost impossible to include a pop-culture reference without invoking this trope in relation to someone. Some examples are listed below.
- In one episode, Jerome Whitaker makes a reference to his actor John Lithgow's character from Footloose. ("I'm sorry, Mr. Small-Town Preacher, is there a law against dancing?")
- In a sixth season episode, a gullible character talks about getting a part on Lost, yet a few episodes earlier, we met a friend of the group nicknamed "The Blitz" played by Jorge Garcia.
- Ted name drops ER in the Season 1 finale. Josh Radnor guest starred as a Patient of the Week during its ninth season. Additionally, when Ted's father is introduced in Season Two, he's played by Michael Gross, who appeared a few times throughout the series as Dr. Carter's father.
- In the season 2 finale, Marshall mentions he finds bald guys cool like Britney Spears. Britney plays Stella's assistant for two episodes in Season 3.
- During the Season 3 premiere, a Mandy Moore song is playing on a radio while Ted is approaching his Girl of the Week. Three guesses on who she is played by.
- During the show's second season, a minor character mentions 27 Dresses. Fast forward to Season 5, Ted and his Girl of the Week played by Judy Greer, who was a main cast member on that film, watches a movie titled The Wedding Bride, a film within the show which stars Malin Åkerman, another 27 Dresses main cast member (though it should be noted Akerman appeared as herself).
- Barney mentions The Smurfs in Season 2. The 2010 movie reboot is headlined by Neil Patrick Harris. Harris' wife in said film is played by Jayma Mays, while Smurfette is voiced by Katy Perry. Both women guested as a Girl of the Week in Seasons 1 and 6 respectively (with Mays returning in the final season). Tim Gunn, who appears As Himself, is also included in the film.
- The show also makes occasional Star Trek references. Marshall's mother is played by Suzie Plakson, who was not only a mainstay on Star Trek: The Next Generation, but was one of the franchise's resident "hat-trick" actors, appearing again in Voyager and Enterprise. Ted's Love Interest in Season 6 is played by Jennifer Morrison, who played Captain Kirk's mother in the film reboots. And speaking of the reboot films, John Cho (who played Hikaru Sulu) guest-starred during Season 3.
- In the Season 3 Thanksgiving Episode, Ted mentions the James Bond film series. Jane Seymour (Actress), who plays Marshall's college professor, played the main Bond Girl of Live and Let Die.
- In a season 8 episode, Mickey Aldrin mentions his plans to watch Breaking Bad. Bryan Cranston, who plays Hammond Druthers, stars as that show's Villain Protagonist. Bob Odenkirk, who plays Arthur Hobbs, plays a major character there who even got his own Spin-Off.
- In the summer of 2011, it was discovered that reruns of the show contained retroactive product placement - ads for timely 2011 products inserted into old episodes. This included a scene where Marshall stood in front of an ad
for Bad Teacher, a film starring Marshall's actor Jason Segel. - At one point, the characters mention going to a Katy Perry concert. Katy Perry guest stars in Season 6 as Zoey's cousin, whom they refer to as Honey.
- Barney mentions the Hallmark movies at one point. Notable cast members who starred in their productions are Ashley Williams (Victoria), James Van Der Beek (Simon Tremblay), Danica McKellar (Trudy), Jane Seymour (Actress) (Professor Lewis), Erin Cahill (Heather Mosby), Michael Gross (Alfred Mosby), Amy Acker (Penelope), and JoAnna Garcia Swisher(Maggie).
