Donna became the girlfriend and next-door neighbor of Eric Forman (Topher Grace).
Randy Pearson (Josh Meyers), who was introduced in the eighth and final season of the series, became Donna's third love interest after Grace left the series.
She showed off the significant piece of jewelry - a gold band with large solitaire diamond - as she linked arms with the Warcraft star.
Laura Prepon might have been sporting a huge diamond on her ring finger when she attended the New York premiere of The Girl On The Train, but it was her dress that really dazzled us!
Unfortunately this AW16 piece isn't available online, but click (right) to shop the collection over at Saks Fifth Avenue.
Or go green on your next night out in one of the lookalike lace dresses we've got lined up for you in the edit below.
The red carpet event was a glamorous affair, with Emily Blunt wearing a green Prada gown and Haley Bennett rocking a ruffled dress by Altuzarra.
But you can never go too far wrong with a little lace number like Laura's.
In mid-2012, Prepon signed on to play Alex Vause, a former drug importer and girlfriend of Piper Chapman, in the Netflix original comedy-drama series Orange Is the New Black, based on Piper Kerman's memoir Orange Is the New Black: My Year in a Women's Prison. In 2016, Prepon and nutritionist Elizabeth Troy co-wrote The Stash Plan, a wellness book that draws on Prepon's experiences eating organic foods since she was a child, and her struggles with weight, low energy, and digestive issues.
It's by Nha Khanh and we love the chic shade of teal.
The sleeveless style, midi length and vertical stripe on the top half elongates the figure, and when teamed with a black box clutch and pointed heels, it's a great look.
Laura Prepon (born March 7, 1980) is an American actress, director, and author.
She is best known for her role as Donna Pinciotti in all eight seasons of the Fox sitcom That '70s Show (1998–2006), and for her portrayal of Alex Vause in the Netflix original comedy-drama series Orange Is the New Black (2013–present). She made her film debut in 2001 with the independent film Southlander.
Prepon co-starred with Bryan Greenberg as Hannah Daniels in the ABC drama October Road, which debuted March 15, 2007.