1999 Colorado Rockies season

The Colorado Rockies' 1999 season was the seventh for the Major League Baseball (MLB) franchise located in Denver, Colorado, their seventh in the National League (NL), and fifth at Coors Field. The team competed in the National League West, finishing in fifth and last place with a record of 72–90. Jim Leyland, a longtime manager in MLB, debuted as the Rockies' new manager, and resigned following the season.

The Rockies, along with the San Diego Padres, made MLB history on Opening Day, April 4, 1999, by playing a contest in Estadio de Béisbol Monterrey in Monterrey, Mexico, making it the first Opening Day game held outside of the United States or Canada. Larry Walker won his second batting title by leading MLB with .379 average, setting a Rockies' club record, and the fourth-high single-season average since Ted Williams hit .406 in 1941. Besides winning the batting championship, Walker also led the major leagues in on-base percentage (.458), and slugging percentage (.710), becoming the first player to lead MLB in all three categories since George Brett in 1980, and the first National Leaguer since Stan Musial in 1943. Despite the team hitting quite well and appearing in the league's top 4 teams in hits, runs, and batting average, the team's performance was poor; the pitching staff performed awfully, allowing 1028 total runs - a mark that, as of 2023, has not since been surpassed by any team. The team set franchise records in earned runs surrendered, walks issued, hits allowed, and ERA. The pitching staff combined for an ERA of 6.01, a new franchise-worst record that has also not since been surpassed by any team.