The Old House at Home, in Locksway Road, Milton, marked its reopening night on Saturday.
Music from Kojak’s Revenge blasted through the pub as the celebration rocked.
Charlotte Edmonds, 27, from Waterlooville, was with her sister Hollie Edmonds, 25, and their brother George Harding for his 19th birthday.
Charlotte said: ‘We’ve come to support it.
‘It’s good to be here to support it as it’s been shut down but brought back to life.’
George added: ‘It’s such a shame to see so many pubs close in Portsmouth so I’m glad to celebrate my birthday here on St George’s Day.’
The pub unexpectedly shut on April 3 when the landlord, Steve Lant, announced he had gone bust.
But it reopened on April 13 after entrepreneur Steve Hudson snapped up the pub.
Neil Davies, known as Ralph, was at the pub for its official re-opening.
He was a previous co-owner of the pub with Mark Otton between 2007 and 2010.
The 49-year-old, of Hilsea, said: ‘It’s great. I’ve been drinking here for 28 years.’
Management have been amazed by the support since reopening.
Chris Foulger, who was on the door on Saturday, said: ‘The response has been fantastic.’
Amid the party the Milton Homing Society were having a meeting in their headquarters in the grounds of the beer garden.
Mick Johnson, secretary of the pigeon group, said: ‘It’s very good to have it open, we’re well pleased.
‘We were making contingency plans and we didn’t want to. We’re an integral part of the pub.’