On July 9, 2015, Aldridge signed a four-year, $80 million contract with the San Antonio Spurs. Upon being acquired by the Spurs, Aldridge was granted the number 12 jersey despite it having been retired for Bruce Bowen. Bowen gave Aldridge and the Spurs his blessing to unretire the number for him. He made his debut for the Spurs in the team's season opener on October 28 against the Oklahoma City Thunder. In just under 32 minutes of action, he recorded 11 points and 5 rebounds in a 112–106 loss. On November 11, he returned to Portland for the first time as a Spur, recording 23 points and 6 rebounds in a 113–101 win over his former team. On February 1, 2016, he scored a season-high 28 points in a 107–92 win over the Orlando Magic, helping the Spurs win its 35th straight home game (dating to March 2015), good for the sixth-best streak in league history. He topped his season-high mark two days later, scoring 36 points in a 110–97 win over the New Orleans Pelicans. With the win, the Spurs moved to 27–0 at home to start the season, snapping a tie with the 1977–78 Portland Trail Blazers for the best home start among Western Conference teams. On February 8, he was named the Western Conference Player of the Week for games played Monday, February 1 through Sunday, February 7. He averaged 26.0 points, 7.3 rebounds and 2.5 blocks while shooting .597 (37–62) from the field and .909 from the free throw line to help the Spurs go 4–0 for the week.