Competing in her sixth final in a row for the Catalan side, the 32-year-old was the cornerstone of a Barcelona team that scored four times in the second half to beat Lyon, the competition's most successful club with eight titles.
"The midfielder's 14-goal contributions were more than any other player; she scored seven times and assisted seven goals during Barcelona's successful campaign, which culminated in a 4-0 win against Lyon in the final," the technical group said in its motivation statement.
Putellas was also included as one of five Barcelona players in the Team of the Season, and 18-year-old Lyon midfielder Lily Yohannes was named "revelation of the season" by the technical group after her performances in Europe helped Lyon to reach a 12th Champions League final.
UEFA Women's Champions League Team of the Season
Goalkeeper: Cata Coll (Barcelona)
Defenders: Emily Fox (Arsenal), Wendie Renard (OL Lyonnes), Mapi León (Barcelona)
Midfielders: Melchie Dumornay (OL Lyonnes), Patri Guijarro (Barcelona), Alexia Putellas (Barcelona)
Forwards: Ewa Pajor (Barcelona), Pernille Harder (Bayern Munich), Alessia Russo (Arsenal)