Yes. From Christina Aguilera to Rihanna to Selena Gomez to Lady Gaga to Miley Cyrus to Beyonce to Girls' Generation, etc. Most influential pop female of the last decade
She's been heavily influenced by Michael Jackson, Madonna, Mariah Carey, Whitney Houston, Shania Twain, Janet Jackson and so, so many more.
Ariana Grande said in an interview that Katy influenced her first album. And technically Katy's also influenced Selena Gomez, Kelly Clarkson, Britney Spears, and Iggy Azalea since she's wrote songs for them.