Click on photos for gallery
Sitting front row at the Italian fashion house's Milan Fashion Week show, the 32-year-old looked elegant in a classic camel coat over a brown silk one-shouldered jumpsuit.
"It's so soft and comfortable. I love their clothes," enthused Katie, who was accompanied by her mum.
The stylish brunette seemed particularly impressed with the brand's autumn/winter 2011 collection.
Inspired by classic British wardrobe staples – from the parka and the duffel coat to the biker jacket – the collection featured strapless dresses in sequin-embellished tartan.
For the evening, there were strapless jumpsuits and fringed ball gowns.
It was created for the cool, contemporary woman – epitomised, said MaxMara's British designer Ian Griffiths, by Katie, whose style he described as 'chic and modern'.
Elsewhere in Milan, Prada presented a sexy collection inspired by the Twenties and the Sixties – two of designer Miuccia Prada's favourite decades.
And Italian duo Dominico Dolce and Stefano Gabbana showcased an 'alphabet' collection for their young D&G label.
Letters were painted on the catwalk and the backdrop, appeared as jewellery, and also featured on skirts and boyfriend blazers.