Kearney started all nine matches in Europe this season, scoring six tries and a stunning drop goal in the narrow semi-final win over Clermont Auvergne as Leinster became the first club to defend the title since Leicester in 2002.
"While I am delighted with the recognition, an individual player is powerless without the support of his team-mates," the 26-year-old Kearney said in a statement.
"So I owe this to the Leinster squad, to the management and to all the backroom staff at the club."
Leinster's Heineken Cup triumph was their third in four years and the 42-14 defeat of Ulster was the biggest margin of victory since the competition began in the 1995-96 season.
Kearney, who succeeded team mate Sean O'Brien in winning the individual award, will now prepare for Ireland's three-Test tour of New Zealand in June after he was named in the squad on Monday.