The London brewer and pub company's new pub is the Merchant in Canary Wharf.
The transformation has included a new bar area to cater for the site’s "improved" craft beer range, a new function room, more all-weather outside seating and a games room.
Jonathon Swaine, managing director of Fuller’s Inns, said: “This has been a great site for Fuller’s since we took it on – but the Merchant really brings the pub up to date.
"It is an amazing scheme – we’ve gained extra bar space, a fantastic private function room, a games room and a range of interesting craft beers, complementing the fantastic brands we brew in Chiswick, which should set Canary Wharf’s taste buds tingling.
"Add to that a very interesting range of delicious food aimed at social dining, a great wine list and interesting cocktails, I am excited to introduce all our customers, old and new, to the Merchant.”
The food at the Merchant is focused on making eating a "very social occasion", said a Fullers spokesman, with a mix of dishes, designed for sharing, using fresh, seasonal ingredients.
The menu includes Vietnamese spicy chicken wings and harissa prawns and spiced monkfish, as well as a wide range of vegetarian options such as truffled mac ‘n’ cheese croquettes and quinoa, mint, apricot and pistachio tabbouleh.
The venue will be open seven days a week and includes a full breakfast menu. It officially opened on Monday 25 September.
The transformation also brought new management to the pub, with Alison Ross as general manager.
Ross has been with Fuller’s for eight years and has most recently been at the Hydrant, Monument, which she has managed for the past two years during which time she has won the Griffin Trophy, which recognises the Fuller’s Pub of the Year.