In 2005, Kaminska appeared with her brother Christian Kamiński in the TV show Pełną Parą. Later that year, she became a co-host for a local morning children's show called Królestwo Maciusia.
In 2006, Kamińska joined the cast of the TV show Ja wam pokażę! playing the character of Tosia.
In 2008, Kamińska was cast as the character "Ula" in the TVN show BrzydUla, a Polish remake of the internationally acclaimed Betty la fea. Following the original storyline, Ula falls in love with her boss Marek Dobrzański, played by Filip Bobek.
From 2012 Julia has been playing a leading role in the sitcom Reguły Gry (Rules of the Game) based on the US hit Rules of Engagement.
Kamińska won the 11th season of Polish Dancing with the Stars - Taniec z Gwiazdami.
She voiced Rapunzel in Tangled and Judy Hopps in Zootopia.
- Tangled Ever After - Rapunzel