Sir Gareth attended a ceremony at Windsor Castle on Thursday, after being named in the Queen's Birthday Honours list in June.
The 68-year-old former scrum half won 53 caps for Wales from 1967 to 1978.
He also won 10 caps for the British Lions' winning series in New Zealand and South Africa.
At 20 he became Wales's youngest captain, and during his era the Welsh side dominated the Five Nations Championship
Originally from Gwaun-Cae-Gurwen in the Swansea Valley, Edwards spent his playing career with Cardiff RFC.
In 1974 Edwards was named BBC Wales Sports Personality of the year.
After his retirement in 1978, he became Captain on the popular sports quiz, Question of Sport.
He now works as a pundit for both the BBC and S4C.
He is married to his childhood sweetheart Maureen and they have two sons, Owen and Rhys.
Wales rugby great Gareth Edwards has been knighted by the Duke of Cambridge in recognition of a glittering sporting career and services to charity.