Katy Perry is one of the biggest pop icons of our generation. She has an enormous catalog of hits and even if you’re not her #1 fan, you probably know the words to at least one of her songs (and catch yourself singing along when it comes on the radio).

Katy is celebrating her birthday on October 25th, and we are celebrating Katy’s big day by looking at her biggest music videos.

Let’s take a look back at the 10 most-viewed music videos on YouTube by Katy Perry.

#10 - This Is How We Do - 804 Million Views

#9 - Part Of Me - 994 Million Views

#8 - Wide Awake - 1 Billion Views

#7 - The One That Got Away - 1 Billion Views

#6 - Hot N Cold - 1.3 Billion Views

#5 - Bon Appétit ft. Migos - 1.3 Billion Views

#4 - Firework - 1.5 Billion Views

#3 - Last Friday Night (T.G.I.F) - 1.5 Billion Views

#2 - Dark Horse - 4 Billion Views

#1 - Roar - 4.2 Billion Views