The actress was in the Big Apple to promote her return to the small screen in a new show called The Crazy Ones, in which she stars alongside Robin Williams, and we're sure she turned a few heads in her NYC wardrobe while at it.
For her appearance on the Late Show with David Letterman, Sarah donned a pretty and feminine white dress that featured a metallic ruffle around the waist as part of the popular peplum trend.
She matched her heels with the metallic ruffle and simply styled her blonde hair by pinning up the sides.
Later that evening, the mum-of-two (who is married to fellow actor Freddie Prinze, Jr) changed into a sexy black ensemble and flashed plenty of leg.
She sported a loose fitting black top and paired it with some silk patterned shorts that could barely be seen underneath her long vest, giving the illusion of a little black dress.
36-year-old Sarah completed her look with a pair of black heels and curled her locks so that they appeared voluminous and bouncy.
Yesterday (1 October), was turned out to be an eventful 24 hours for the former Buffy The Vampire Slayer star, since she finally took the plunge and joined Twitter.
Despite only having a Twitter account for less than a day, Sarah has already racked up over 21,100 followers - although she did admit to feeling nervous about her foray into social networking initially.
Her first tweet read: "Why is sending this first tweet scarier than going on the @LateShow?"
We're sure she'll get the hang of it soon!
Which of Sarah's NYC outfits do you prefer? Let us know below!