After a quick courtship, Cuoco is engaged to tennis pro Ryan Sweeting, her rep confirms.
The 27-year-old actress and 26-year-old Sweeting began dating about three months ago.
The engagement comes a few days after Cuoco took Sweeting as her date to the Emmy Awards. At a pre-Emmy event, Cuoco called Sweeting the "greatest date ever" on a photo posted to her official Twitter and Instagram accounts.
News of the proposal was first reported by Us Weekly.
It will be the first marriage for both.
"The Big Bang Theory" returns for its seventh season on Thursday.