The grant has been awarded to fund development work ahead of the theatre's 250th anniversary next May.
The money will be used to catalogue historic theatrical memorabilia and survey a "thunder run" -  a tunnel high above the ceiling used to roll metal balls down to replicate thunder.
Director Emma Stenning said she hoped the theatre would become an attraction on a par with Bath's Royal Crescent.
"We'll be stripping back bits of plaster to check what's behind and investing in the conservation of the theatre's extraordinary archive of theatrical memorabilia, dating back to the early 18th Century," she said.
"I'm hoping we'll really be uncovering the hidden treasure that is Bristol Old Vic so people can come to us as a heritage destination as they might go to the SS Great Britain or the Royal Crescent."
Once initial work is complete, the theatre is hoping to secure a further £2.5m from the Heritage Lottery Fund (HLF) to help pay for a £12m refurbishment.
Nerys Watts, head of HLF South West, said the redevelopment project would ensure the theatre was in "great shape" to mark its 250th anniversary.
"We're hugely supportive of these plans to protect an 18th Century Bristol landmark and to open it up for many more people's enjoyment," she said.
Bristol's Old Vic Theatre is set to receive £220,500 of lottery funding.