Weymouth Pavilion Community Interest Company (CIC) and Greenhill Community Trust have been granted 30-year leases by the borough council.
The latter will take over the running of Greenhill chalets, gardens, tennis courts, putting green and cafe.
Councillors have agreed to pay Â£250,000 to repair Weymouth pavilion's roof.
Weymouth and Portland borough councillor James Farquarson, said the building - which had been ear-marked for demolition four years ago - had not been a "top priority" for the council and it had suffered.
He said the lease would allow the group to apply for grants to carry out repairs and the pavilion now had "a good future ahead of it".
Councillor Andy Blackwood said deteriorating metalwork in some of the beach huts was a "major concern".
However, he added the authority was handing over responsibility for management and maintenance to the trust "in the hope it will secure the future of the chalets".
Weymouth Pavilion CIC has not yet responded to a BBC request for comment.
Community groups will take over the running of an under-threat pavilion theatre and a number of beach huts in a bid to "secure" their future.