The 22 year old was named Favorite Movie Actress for her turn in The Twilight Saga: Breaking Dawn - Part 2, and she also picked up the Favorite Female Buttkicker trophy for Snow White and the Huntsman.
Stewart was on hand to receive the honours, and she was inadvertently treated to the ceremony's traditional sliming by hugging award presenters Sandra Bullock and Neil Patrick Harris, who had been covered in the green goo.
Rapper Pitbull was the first celebrity to be covered in slime after he performed with Christina Aguilera to kick off the Los Angeles prizegiving, which was hosted by actor Josh Duhamel.
One Direction missed the ceremony as they were performing a concert in Birmingham, England on Saturday night, but they were named Favorite Music Group and also landed Favorite Song for What Makes You Beautiful.
In other music categories, Justin Bieber bagged the Favorite Male Singer accolade, while Katy Perry picked up the female equivalent.
The full list of winners at the Nickelodeon Kids' Choice Awards is:
Favorite Movie - The Hunger Games
Favorite Movie Actor - Johnny Depp (Dark Shadows)
Favorite Movie Actress - Kristen Stewart (The Twilight Saga: Breaking Dawn - Part 2)
Favorite Animated Movie - Wreck-It Ralph
Favorite Voice from an Animated Movie - Adam Sandler (Hotel Transylvania)
Favorite Male Buttkicker - Dwayne Johnson (Journey 2: The Mysterious Island)
Favorite Female Buttkicker - Kristen Stewart (Snow White and the Huntsman)
Favorite Music Group - One Direction
Favorite Male Singer - Justin Bieber
Favorite Female Singer - Katy Perry
Favorite Song - What Makes You Beautiful by One Direction
Favorite TV Show - Victorious
Favorite Reality Show - Wipeout
Favorite Cartoon - SpongeBob SquarePants
Favorite TV Actor - Ross Lynch (Austin & Ally)
Favorite TV Actress - Selena Gomez (Wizards of Waverly Place)
Favorite Male Athlete - LeBron James
Favorite Female Athlete - Danica Patrick
Favorite Villain - Simon Cowell (The X Factor)
Favorite Book - The Hunger Games series.
Favorite Videogame - Just Dance 4
Favorite App - Temple Run.