The 1999 Houston Astros season was the 38th season for the Major League Baseball (MLB) franchise in Houston, Texas. The Astros won their third consecutive National League Central title on the final day of playing regular season games in the Astrodome on October 3. This was the first time they had made the postseason in three straight seasons; they would not do so again until 2019. It was the 35th and final season playing in the Astrodome as their home ballpark.

The NRG Astrodome, formerly and also known as the Houston Astrodome or simply the Astrodome, was the world's first multi-purpose, domed sports stadium, located in Houston, Texas, United States, with a record attendance of 68,266 set by George Strait in 2002.