Dallas, who can play as a winger or as an attacking midfielder, has been voted as the Leeds United Players’ Player of the Year.
Lafferty, who joined Championship side Birmingham City on loan from Premier League outfit Norwich in March, plays with Dallas for the Northern Ireland national football team.
The former Rangers forward has taken to Twitter to congratulate Dallas on winning the prestigious award.
Dallas joined Leeds from Championship rivals Brentford in the summer of 2015.
The 25-year-old Northern Ireland international attacker has scored five goals and created 51 chances in 44 league matches for the Whites this season.
The former Crusaders player has a pass accuracy of 75% and a shot accuracy of 41%, and has won 22 headers, 29 dribbles and 39 tackles.
Leeds are 12th in the Championship table at the moment with 58 points from 45 matches.