The gourmet pie business, which opened the 100-cover restaurant at The O2 on 8 June, has secured a site at Birmingham Grand Central which it plans to open in September.
Founder Martin Dewey said The O2 site, opened 'on the back of successful recent fundraising' was paving the way for further expansion for Square Pie. As well as the Birmingham site, there are plans for another five restaurants to open across the UK in 2016.
He said: "Our big plans for 2015 have only just begun. We’re really excited with the O2 restaurant opening I think it will become our busiest restaurant, with the exception of our five days at Glastonbury every year!
"Over the next few years we are looking to significantly grow the business both by opening more of our great restaurants and building on the successful launch of our pies and mini pie canapies into supermarkets and foodservice."
Square Pie, founded by Dewey in 2001, has been present at every Glastonbury Festival since 2002. It currently operates five restaurants - at Old Spitalfields Market, Westfield London, ExCel Exhibition Centre, Westfield Stratford and The O2 in Greenwich.
Restaurants serve a range of 10 freshly baked pies with mash and other sides such as 'steamed then baked’ jacket potatoes, sausages & mash and macaroni cheese. The company also sells into retail and has a range for foodservice.