The workers had been in a legal strike position since Friday morning.
The festival says major issues were wages and contracting out.
Ann Swerdfager, a Festival spokeswoman, says the deal, which still needs to be ratified, gives the workers a 5.5 per cent wage increase over two years.
It also contains a clause agreeing not to contract out call centre work for the duration of the contract.
The festival's 2012 season opens officially on Monday with a performance of Shakespeare's "Much Ado About Nothing."