Kate Middleton, Happy 31st Birthday! Love, InStyle

By Sharon Clott Kanter

Jan 09, 2013 @ 9:00 am

Dominic Lipinski/Getty; James Whatling/Splash News; Mark Cuthbert/UK Press/ABACAUSA.COM; David Crump/AFP/Getty; Chris Jackson/Getty

It's one of the best days of the year—Kate Middleton’s birthday! The Duchess of Cambridge turns 31 today, and this year is going to be more special than ever. Not only is she happily married to a Real Prince (oh, hey William) and owns one of the best wardrobes in the world (filled with Alexander McQueen, Alice Temperley, and Jenny Packham galore!), she'll also become a mom when she delivers her first child this spring. So, let's all wish a big, big, big, happy birthday to Catherine today—may this year bring her (and us, by proxy) even more happiness!

Plus, see Kate's most memorable outfits ever! You'll love these pictures.