Datsyuk scored 27 goals and amassed 87 points in 79 regular-season games while serving only 20 minutes in penalties.
In a vote by selected members of the Professional Hockey Writers' Association, the Russian centre got a total of 705 points based on 38 first-place votes, 26 second-place votes, 18 thirds, 15 fourths and eighth fifth-place votes.
Detroit GM Ken Holland accepted the trophy on behalf of Datsyuk during the league's annual awards ceremonies Thursday night.
Martin St. Louis of the Tampa Bay Lightning was runner-up with 513 points (26-19-19-6-7), and Joe Sakic of the Colorado Avalanche was third with 354 (17-17-7-9-3).
The Lady Byng Trophy is for the player adjudged to have exhibited the best type of sportsmanship and gentlemanly conduct combined with a high standard of playing ability.
The winner was selected in a poll by the Professional Hockey Writers' Association at the end of the regular season. The winner receives $10,000 and the runners-up $6,000 and $4,000.
The trophy was first presented in 1925 by Lady Byng, wife of Canada's governor general at the time, to Frank Nighbor of the Ottawa Senators.