The Oscar nominee, 45, makes her animation debut as Kitty Softpaws in the Shrek spin-off alongside the Spanish actor, a long-time friend, who reprises his role as the famous cat in their sixth collaboration together.
"There's never a dull moment with Antonio," she said at the film's UK premiere in London.
Dressed in a black tuxedo suit by Yves Saint Lauren and hat, she added: "Just when you think you're becoming bored of him, he becomes crazier."
The appreciation was evidently mutual, with Antonio saying: "She was great. She is someone that I love - we have been friends for over 18 years - so the whole ride was different."
Salma, who is mother to four-year-old daughter Valentina, enjoyed her first foray into animation.
She said: "It couldn't have come at a better time because now I have my daughter. She loves it. It's very exciting for her being on tour with us and seeing everything. Sometimes we have the stuffed animals walking around."
She added: "She loves being around Antonio. She's in love with him."
Directed by Chris Miller, Puss In Boots, which also stars Zach Galifianakis and Billy Bob Thornton, opens in cinemas on Friday December 9.
SLIDESHOWS: Salma Hayek and Antonio Banderas fool around on the red carpet...