'Friends' Biggest and Most Surprising Guest Stars!

A lot of really many famous faces appeared on 'Friends' over the years.

Friends was the biggest show on TV during it's run, so it's not too surprising that it also attracted some of the biggest names in Hollywood. In fact, the show brought out some real star power during its 10-season run.

From A-listers to screen legends, the show featured cameos from movie stars, music divas and comedy icons, who each left their own impression on the fabric of the series.

Some of the biggest cameos came from Oscar winners like Julia RobertsReese Witherspoon, Robin Williams and George Clooney, while others featured some of the cast members' significant others (at the time), like Brad Pitt and David Arquette.

The long-running series also featured stars in some recurring roles, with Paul Rudd, Aisha Tyler and Christina Applegate all playing characters who had more than just a passing interaction with the beloved series.

With the long-awaited Friends: The Reunion coming to HBO Max on May 27, ET is reflecting on all of the best and most memorable guest stars from the sitcom's long run.

Click through the gallery below for a round-up of the 40 best celeb cameos in the history of Friends.

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