The 2008–09 National Indoor Soccer League is the inaugural season for the league and the 31st anniversary of professional Division 1 indoor soccer in the United States. The members of the NISL's first season are the Baltimore Blast, the Massachusetts Twisters, the Monterrey La Raza, the Philadelphia KiXX, and the Rockford Rampage. The Orlando Sharks were supposed to play, but due to scheduling conflicts with the Amway Arena the Twisters took the Sharks' spot for the season.

The league kicked off on November 15, 2008, with the Philadelphia KiXX defeating the Massachusetts Twisters 34-11 and the Baltimore Blast defeating the Rockford Rampage 14–4. The regular season concluded March 29, 2009.

Each team played eighteen games, nine home and nine away. La Raza also played, and won, the Copa América against PASL-Pro and PASL-Premier teams.

Blue indicates bye into the NISL Championship
Green indicates playoff berth clinched