Councillors have given the go-ahead to a £235m development at Brighton Marina, which includes a 40-storey tower block.
The red line indicates the changes made to the original plans
The planning committee voted nine to three in favour of the scheme despite a protest outside at Hove Town Hall.
Objectors, led by Brighton Marina Action Group, said the project would turn the seafront marina into a "gigantic housing estate".
The scheme had been modified since an earlier application was rejected last year by Brighton and Hove City Council.
The revised scheme reduces the height of the centre section and removes three buildings.
The number of apartments has been reduced from 988 to 853 and car parking spaces increased from 176 to 496.
The scheme also now includes extra residents' gardens, sports facilities and children's play areas.
"It is a big and bold scheme and it was always meant to be," said Andrew Goodall, managing director of the marina's owner, Brunswick Developments.
"It will have one of the largest, if not the largest, residential building in the South East outside London.
"We want to integrate Brighton Marina into the city more and more."
The protesters have vowed to continue their fight.
"All the reasons for the council refusing the original scheme apply equally strongly to the new one," said Peter Martin, spokesman for the action group.
"This proposal still represents a tsunami of gross and over-dense development."
The city council received 322 letters of objection from local groups and residents and 381 letters of support, which included 55 from businesses.