The Royal Baby was born on Monday, but Taylor Swift is doing all she can to ensure folks don't forget about another celebrity born on July 22.

"Happy 21st birthday to my friend, and the closest thing I've ever had to a sister, @selenagomez!!" Swift Tweeted Monday, along with the following cute photo of the stars:

Posted in: Selena Gomez

Taylor Swift Biography

Taylor Swift and Friend
Taylor Swift is the next big thing in country music. She hails from Pennsylvania and has a younger brother named Austin. Personally,... More »
Full Name
Taylor Swift

Taylor Swift Quotes

I think it's kind of fun to call out your ex-boyfriends. Like why do this if you're not gonna take the opportunity to always have the last word. It's so much fun.

Taylor Swift

I saw that documentary on Britney Spears, and I feel bad for her—she can't leave her house!

Taylor Swift