The 1989 Southwest Outdoor Soccer League season was the first outdoor and fourth overall season of the Southwest Indoor Soccer League.
After running three winter indoor seasons beginning in 1986, the Southwest Indoor Soccer League added its first summer outdoor season in 1989. With the move outdoors, the league added the Colorado Comets and Tulsa Renegades who quickly proved their worth when they finished at the top of the standing. The move outdoor brought a short-lived name change as the league rebranded itself as the Southwest Outdoor Soccer League. The season began on May 27, 1989.