Held on Saturday at Basilica of St. Patrick's Old Cathedral in Manhattan, wedding guests included Woody Allen, Tina Fey, Mariska Hargitay, Lorne Michaels and Jimmy Fallon, according to media reports.
Famous relatives of Baldwin - his brother Billy and Stephen and his 16-year-old daughter Ireland - also attended.
Baldwin, 54 and previously married to actress Kim Basinger, met Thomas, 28 and a yoga instructor, at a New York raw-food restaurant in February 2011.
The seasoned actor walked up to Thomas, took her hand and said, I must know you. At first, however, the yoga expert had some reservations about her age difference with Baldwin, according to the New York Times.
Thomas and Baldwin are both graduates of New York University; the wedding reception was held at one of the university's buildings in Manhattan.
Below are various photographs of Thomas and Baldwin.
Baldwin and his Thomas pose at the premiere of Rock of Ages at the Grauman's Chinese theatre in Hollywood. 09/06/2012. (PHOTO: Reuters)
Actor Baldwin and Thomas arrive for amfAR's Cinema Against AIDS 2012 event in Antibes during the 65th Cannes Film Festival. 24/05/2012. (PHOTO: Reuters)
Actor Alec Baldwin and Hilaria Thomas enter the show room at the 18th annual Screen Actors Guild Awards in Los Angeles. 30/01/2012. (PHOTO: Reuters)