Winning the One To Watch Award means judges believed the pub was likely to enter the main list in the future.
The Oxford Blue wowed the judges with its focus on game, extensive drinks offer and spectacular customer service.
General manager Daniel Crump said: "When the four of us left London, we left with strong experience in high end restaurants. We believe in the great British pub and are extremely passionate about reviving and maintaining the British pub's reputation.
"To be awarded two accolades from the most respected awards in the pub industry has been one of the biggest highlights for us since we started on this journey. It has (if at all possible) made us even more hungry to make the Estrella Damm Top 50 Gastropubs awards organisation and all of their followers proud."
Category judge and editor of Top 50 Gastropubs Nicholas Robinson said: “The Oxford Blue in Old Windsor is a stunning new gastropub, pretty much built from scratch to the designs of the four partners behind it.
“Chef Steven Ellis loves to cook with game, incorporating it into classic dishes and shouting about its credentials to those who are quick to shun it."
Wealth of talent
He added: “There is a wealth of talent in Ellis’s kitchen, while the front-of-house team, led by one of the friendliest men in pubs – Daniel Crump – emanates genuine care and interest in your dining needs.
“It is not far from the centre of Windsor or the luscious part of the River Thames, perfect for a post-lunch walk."
Obsessed with game
Robinson said: “The gastropub’s wine list, beer, spirits and soft drinks offerings are full and interesting, making this a pub for anyone.
“Chef-proprietor Steven Ellis is obsessed with game. If there’s a dish not associated with it, then leave it to him to make it work.”