The 2018 North American Soccer League season would have been the eighth season of the modern North American Soccer League (NASL), but was canceled after the league was denied a preliminary injunction to prevent the loss of their Division II status.
The previous season's champion was the San Francisco Deltas who defeated the New York Cosmos in Soccer Bowl 2017. The Deltas folded after the 2017 season, citing financial difficulty and the uncertainty surrounding the future of the league.
Prior to the 2017 season, the league's Division II status was downgraded by the United States Soccer Federation (USSF) to a provisional sanctioning after league membership decreased to less than the 12 required by the Federation. At the same time, the USSF also promoted the former Division III league, the United Soccer League (USL), to a provisional Division II sanctioning.
During the 2017 season, the NASL announced two more expansion teams in California: San Diego 1904 FC in San Diego and California United FC in Orange County. The additions would have brought the 2018 league members only up to 10, still short of the 12 required for Division II.
On September 5, 2017, the USSF announced the NASL would not be granted Division II sanctioning for the upcoming 2018 season. Two weeks later on September 19, the NASL announced it was filing an antitrust lawsuit against the USSF over the sanctioning. A federal judge denied the league's request for a mandatory injunction against the USSF to regain its Division II designation in November 2017.
Two weeks later on November 16, North Carolina FC left the league to join the USL. FC Edmonton and the San Francisco Deltas then announced they would cease professional operations citing the uncertainty about the divisional status of the league. Indy Eleven would also join the USL in January 2018.