Various schemes to redevelop the Tropicana outdoor pool and leisure facility have failed since it closed in 2000 due to falling visitor numbers.
North Somerset Council unanimously voted through proposals to get the building "back up and into use".
Councillor Tony Lake said work would start within "weeks if not days".
The proposals for the Tropicana will allow the building to be used for a variety of leisure activities and events throughout the year.
Money for the redevelopment will come from an existing budget of Â£748,000 set aside for the site which was approved by members in 2011.
The work will include roof repairs, rewiring, heating, mending of the external fabric and overall light refurbishment works.
Mr Lake said the council also hope to see the pool redeveloped in the longer term, subject to a viable business plan coming forward.
There has been a pool on the seafront in Weston since the 1930s.
As late as the 1980s, families thronged to the Tropicana to experience its state-of-the-art wave machine.
A building on Weston-super-Mare's seafront is to undergo a Â£750,000 refurbishment after lying derelict for 14 years.