Wembanyama, who was the first pick in last year's NBA Draft, averaged 21.4 points, 10.6 rebounds, 3.9 assists and a league-high 3.6 blocks per game this season.
The NBA said Wembanyama received all 99 first-place votes from a media panel, making him the first unanimous rookie of the year since Karl-Anthony Towns in the 2015/16 season.
Wembanyama is the first player from France to win the NBA's Rookie of the Year award and the third player to earn the honour as a member of the Spurs, joining David Robinson (1989/90) and Tim Duncan (1997/98).
Wembanyama is only the second rookie to lead all NBA players in blocks per game in a season, joining Manute Bol (1985/86).
Wembanyama is also one of three finalists for the Defensive Player of the Year award along with Minnesota's Rudy Gobert and Miami's Bam Adebayo. The winner will be announced on Tuesday.
