The council wants to expand its existing sites at Lansdown, Newbridge and Odd Down to provide an extra 1,120 parking spaces.
The preferred site for the new park-and-ride base is at Mill Lane in Bathampton, which would provide 1,400 spaces.
But residents around Bathampton believe it would have a devastating effect on local wildlife and would do little to reduce traffic problems.
Around 100 people including schoolchildren from Bathampton and Batheaston Primary Schools attended a protest against the plans.
Batheaston resident Alison Millar said: "The Bathampton Meadows are an essential green space. They provide an important seasonal wetland habitat.
"They give an identity to Bath and the outlying villages by providing a break between potential urban sprawl.
"The beautiful approach to Bath along the Avon Valley is as important to the character of the city as any of the attractions that are within the World Heritage Site."
The protesters have the support of the South West branch of the Campaign to Protect Rural England.
Vice-chairman of the organisation, Henrietta Sherwin, said: "Park and rides were conceived in the early 1970s before transport policy had moved towards demand management and trying to restrict car traffic.
"They are an out-of-date policy and no substitute for the development of an integrated public transport network, particularly with an ageing population.
"Now they are sold as providing transport choice but the question needs to be asked, choice for whom?
"Should limited resources be spent to encourage car access to Bath? Park-and-rides are expensive and have a considerable environmental impact but a very marginal congestion benefit."
The cost of the expansion would be funded by the £54 million Bath Transportation Package.
The council expects the park-and-ride expansion to tackle the congestion problems caused by 27,000 people travelling in and out of Bath by car for work every day.
It says the expansion of the park-and-ride network around the city is needed to combat the predicted 14 per cent increase in 10 years of cars travelling through the city during the morning rush hour.
The enlarged Bath park-and-ride network would include 390 new spaces at Lansdown, 500 new spaces at Newbridge and 230 new spaces at Odd Down.
Newbridge residents have already objected to the proposals.
Cllr Charles Gerrish, B&NES cabinet member for customer services, said: "The expansion of Bath and North East Somerset Council's park-and-ride services is just one element of the effort to support better public transport.
"The council's aim to improve transport and the public realm is undermined by limited overall park-and-ride capacity.
"The council's park-and-ride provision requires a radical overhaul through the addition of more than 2,000 spaces.
"Workers and visitors from outside Bath, including in our own communities of Keynsham, Midsomer Norton and Radstock, and the rural villages, must have better access to their jobs and local services.
"In turn, this will support the place the community wants Bath to be – one where the congestion is reduced and pedestrian and cycling access is improved, with space for public transport to move.
"The likely alternative is gridlock in a decade if these improvements, with others such as better conventional bus routes and the bus rapid transit, do not go ahead."
A public exhibition giving details of the park-and-ride proposals will be held at the Guildhall from November 6 to 8.