The former Frasier star, 56, wed the flight attendant in a lavish ceremony at New York's Longacre Theater, where he recently wowed critics in La Cage aux Folles.
They celebrated their wedding with a lavish reception at New York's famous The Plaza Hotel, with guests including his son Jude, with ex-wife Camille, and his daughter Spencer from a previous relationship. However, the star's youngest daughter Mason was not present.
Toasting the newlyweds with a speech, actress Spencer revealed her father had her full support marrying his new love just weeks after finalising his divorce from third wife Camille - as she hadn't ever seen him so happy, according to America's Life & Style magazine.
The publication claims Spencer told guests, ""Since my father met Kayte, there has been a visible change in him. I can truly say I attest it to Kayte. She set him free, inspired him.""
All the guests enjoyed a sumptuous three-course meal and danced to 1970s tunes, before Grammer wowed them with his karaoke rendition of What Kind Of Fool I Am.