Hayden Panettiere struck a pose at the 2012 Emmys at the Nokia Theatre L.A. Live on Sunday evening, and judging from this stunning and sophisticated outfit, the 23-year-old starlet is all grown up!

Hayden wore a gorgeous blue and gold Marchesa gown, and she accessorized with Harry Winston jewelry, Giuseppe Zanotti shoes, and a Judith Leiber bag. Hayden hasn't been on the small screen since her glory days in NBC's Heroes, but she'll make her return to the tube on October 10 for Nashville, where she plays a teen country music diva. Um, can't WAIT for this one!