About 100 people packed into Monday night’s council meeting to hear the debate and cheered and applauded when the decision was made.
Most of them had taken part in a demonstration outside the Guildhall before the meeting to show their support for the motion, organised by the campaign group, eXtinction Rebellion.
The declaration means the council has pledged to make the council carbon neutral by 2030 and will call on the government to provide powers and resources to make that possible.
It is requesting a council committee to make an action plan in pursuit of the objectives and report back in six months.
Member of eXtinction Rebellion, Adam Ship, urged the council to declare a climate emergency, make sure it took action and not words and accepted the help of members of the group.
Alan Mosley, who is a county councillor and also the Labour leader of Shrewsbury Town Council, said: “If temperatures rose by two degrees, the impact would be devastating. Scientists have said it is still possible to limit global warming to 1.5 degrees.
“I have just become a great grandfather and this makes one even more aware that this isn’t a here and now problem. We need to leave a legacy of progress for good rather than a recipe for disaster.”
He said Shrewsbury Town Council already did a great deal, planning to install LED street lights and solar lighting in the Quarry and spending £100,000 on footpaths and cycleways as well as looking to bring electric vehicles into its fleet.
There was an addendum to the motion by Councillor Julian Dean calling on Shrewsbury Town Council to withdraw its support for the North West Relief Road.
He said that there had to be a decisive shift in modes of transport away from cars and Councillor David Vasmer said he believed the road would be not only an environmental but a financial disaster.
However the move was voted down with several councillors saying the relief road was needed.
The town's mayor, Councillor Peter Nutting, said it would lead to the removal of about 50-60 per cent of traffic from Smithfield Road in the town centre.
This, he said, would have a huge impact on pollution and the environment in the town.
Councillors voted overwhelmingly to declare a climate emergency and also call on Shropshire Council to do the same.
Oswestry Town Council has already declared a climate emergency.