The three Tigers players were on the shortlist for the March award, with supporters voting Slater the winner via the Goldsmiths Facebook page.
The result was announced at half-time of Saturday’s 27-15 Aviva Premiership victory over London Wasps and Slater was presented with his prize, a Tag Heuer Aquaracer, in the tunnel at Welford Road after the game.
“Thank you to everyone who voted,” said Slater. “I was surprised to win considering how well the team, and in particular, Logo and Niki are playing.
“I am very grateful to win the award and thank you to Goldsmiths for such a generous prize.”
It was Tigers’ sixth Aviva Premiership win in a row and their eighth game in the competition unbeaten. It is a run that has moved Tigers to third in the table with three games remaining, starting with a trip to Harlequins on Friday night.
Slater added: “We’ve done well over the last few games and we need to push on for the final three games.”