The conferment took place ahead of an acoustic concert by the band on Wednesday in the Co Down city, organised in celebration of the award.
Lightbody, described as the city of Bangor’s most famous son, officially received the accolade after signing the Book of Burgesses with mayor Karen Douglas and council chief executive Stephen Reid.
He is a superb role model in the music industry and an ambassador for Northern Ireland
Karen Douglas, mayor of Ards and North Down
Ms Douglas, said: “The decision to bestow the freedom of the borough on Gary Lightbody was made in October 2019 but the pandemic and Gary’s busy touring schedule prevented us from presenting it until now.
“2019 was the year of Ward Park 3 which Snow Patrol headlined and the concert really put Bangor on the international map.
“That one event illustrated Gary’s love of home, his outstanding musical talent, and his commitment to championing new artists.
“He is a superb role model in the music industry and an ambassador for Northern Ireland so it is very appropriate for him to receive the highest honour that Ards and North Down Borough Council can bestow.”
Freedom of the borough is an ancient privilege dating back to the 1600s.
Lightbody was instrumental in the establishment of Oh Yeah Music Centre in 2007, a charity and social enterprise in Belfast, formed as a resource for music makers and to support the music business in Northern Ireland.
He was the first recipient of the award for outstanding contribution to music at the Northern Ireland Music Prize in 2018 and has since talked about his appreciation of the ability to give back to the local music scene.
The launch of the Lightbody Foundation in 2019, in partnership with the Community Foundation for Northern Ireland, has provided funding and helped to support a wide range of voluntary and community groups.
He has been open about his struggles with mental health and depression.
Snow Patrol returned to Bangor for concerts in 2007, 2010 and 2019.