The versatile Northern Ireland international was voted by Whites’ fans for the award after a stellar campaign across a number of positions.
Dallas scored eight goals and bagged two assists across 38 appearances in the top flight and took home the trophy on Sunday night following the final game of the campaign.
“We’ve had an incredible season,” Dallas said during the ceremony. “Football is a rollercoaster. You have highs and lows. The target for us was to achieve the 40-point safety mark and take it from there.
“We always believed in ourselves that we were good enough to achieve a top-half finish. It’s incredible as a newly-promoted side what we’ve achieved.
“We’ve set a bench mark now and we have to push on again.”
On the award itself, he added: “It’s incredible. I’m sort of lost for words. I want to thank everyone who voted for me. It could’ve been anybody. Everybody has been incredible this season. It’s been a difficult year for everyone and for me to win this is unbelievable.
“I want to dedicate my awards to my Granda, who is going through a tough time at the minute. There will be no prouder man than him.”
Dallas was also voted as Players’ Player of the Year by Marcelo Bielsa’s squad and took home the Goal of the Season trophy for his winner against Manchester City at the Etihad.
Leeds rounded off an impressive debut term back in the Premier League with a 3-1 victory over West Brom at Elland Road that saw the club finish ninth in the standings.