Tulowitzki entered spring training prior to the 2007 season competing with incumbent Rockies shortstop Clint Barmes for the starting role. After a spring that saw Tulowitzki win the team's spring training MVP award, along with Barmes struggling offensively, Tulowitzki began the season as the Rockies' starting shortstop. On April 29, 2007, Tulowitzki turned the 13th unassisted triple play in MLB history, during a 9–7 home victory at Coors Field over the Atlanta Braves.
Tulowitzki was named the NL Rookie of the Month for August. On September 10, 2007, Tulowitzki hit his 20th home run of the season, which set the record for most home runs in a single season by a National League rookie shortstop. The previous record was 19, held by Ernie Banks. Tulowitzki hit his first career grand slam on September 29, 2007, in an 11–1 home win over the Arizona Diamondbacks, off of Dustin Nippert. He ended with 24 home runs on the season.
In the 2007 season, Tulowitzki ranked first among NL rookies in at bats (609), plate appearances (678), games (155), hits (177), doubles (33), runs (104), total bases (292), walks (57) and RBIs (99; two ahead of Ryan Braun, in 158 more at bats than Braun). Tulowitzki's 99 RBIs led all National League shortstops (he was three short of a tie for the MLB lead, held by Detroit Tigers shortstop Carlos Guillén). He set an MLB-single season record in RBIs for a rookie shortstop. He finished second behind Braun in OBP (.359). He was third behind Braun and Hunter Pence in batting average (.291), slugging percentage (.479), OPS (.838) and triples (5). Tulowitzki was also third behind Braun and Chris Young in home runs (24) and extra base hits (62), and tied for ninth in stolen bases (7).
On October 1, 2007, in the one-game Wild Card tie-breaker against the San Diego Padres, Tulowitzki went 4-for-7 with three extra-base hits and scored the tying run in the bottom of the 13th inning. The Rockies won the game, 9–8, and entered the playoffs as the NL wild card team. They faced the Philadelphia Phillies in the National League Division Series. On October 4, 2007, in the second game of the series, Tulowitzki and left fielder Matt Holliday hit back-to-back first-pitch homers in the first inning to begin a 10–5 win, and the Rockies headed to Denver with a 2–0 lead in the series. The Rockies went on to complete a three-game sweep of the Phillies, and advanced to the National League Championship Series, in which they swept the Arizona Diamondbacks in four games. Colorado then played the Boston Red Sox in the World Series, which was the first ever World Series appearance in Rockies history. Boston swept Colorado in four games. Tulowitzki batted .195 in the postseason, with a .267 on-base percentage and 15 strikeouts in 41 at-bats.