Her full name is Katheryn Elizabeth Hudson, but she changed it to avoid confusion with actress Kate Hudson.

She grew up in a conservative Christian household, and her first album was gospel music.

She wrote her first song, "Trust in Me," at just 16 years old.

Before fame, she was dropped by three record labels.

"I Kissed a Girl" was initially offered to Jessie J.

She can recite the alphabet backward really fast!

She holds records for being the first female with five No. 1 singles from one album (Teenage Dream).

She has kept locks of hair from Taylor Swift and Miley Cyrus as souvenirs.

She was an extra in the 2001 film "The Princess Diaries" before her music career took off.

She had surgery in 2017 due to vocal cord damage from excessive singing.