Happy birthday, Pippa Middleton! The famous younger sister to the Duchess of Cambridge turns 34 today.

We've admired Pippa's impeccable style over the years, always looking equally chic lighting up formal galas or strolling London streets, and most recently her look has been elevated by a gorgeous art-deco style engagement ring from her fiancé James Matthews.

Credit: Getty (2)

The fit Brit is also often spotted in workout gear as she champions causes near and dear to her heart—she's impressively run a full marathon shortly after completing a 54-mile bike race. But Pippa's no stranger to grueling endurance sport; she and her brother James tackled a 3,000-mile bike ride across the U.S. for charity as part of Race Across America, and recently scaled the Matterhorn, a mountain in Switzerland, in honor of her fiancé’s late brother, raising money for the Michael Matthews Foundation. Her athleticism and admirable abs are always on full display, even while on vacation—this royal-in-law is never short on #fitspo!

All of her athleticism certainly pays off: The star looked stunning on her wedding day when she married Matthews last May.

See Pippa Middleton's changing looks through the years in our gallery.