24 celebrities you probably forgot appeared on 'The Bachelor' and 'The Bachelorette'

• Celebrities often cameo on ABC's "The Bachelor" and "The Bachelorette."
• Some celebrities help out during competitive dates, Mila Kunis, Ashton Kutcher, and Amy Schumer.
• Others perform for the contestants, Dolly Parton, Boys II Men, and Backstreet Boys.

Even celebrities can't stay away from "The Bachelor" and "The Bachelorette."

On the most recent season of ABC's "The Bachelor," Megan Mullally, Nick Offerman, and Billy Eichner joined Colton Underwood for some group dates, and they aren't the first to do so. Musicians, athletes, actors, and comedians often appear on the ABC dating show as part of dates the contestants go on. 

Concert dates and private performances are popular on the series, too. 

Here are 24 celebrities you probably forgot cameoed on "The Bachelor" and "The Bachelorette." 

SEE ALSO: 7 'Bachelor' and 'Bachelorette' stars who broke up on air

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Comedians Megan Mullally and Nick Offerman helped some contestants during a group date on Colton Underwood's season.

Husband and wife Megan Mullally and Nick Offerman told personal stories of their "firsts" and helped contestants share their own "firsts." The women told their stories in front of an audience at Regent Theater in Los Angeles. 

Billy Eichner showed up for a group date in which the women competed in "camp" games.

Eichner, comedian and "Parks and Recreation" star, helped present contestants with their challenges during a group date at "Camp Bachelor." 

Lil Jon joined Becca Kufrin and Blake Horstmann on a date.

Lil Jon supported Becca as she and Blake smashed items that reminded her of ex-fiancé Arie Luyendyk Jr.