The 1990 National Soccer League season was the sixty-seventh season under the National Soccer League (NSL) name. The season concluded on September 12, 1990, with Toronto First Portuguese claiming their third NSL Championship by finishing first in the First Division. First Portuguese would also secure the NSL Canadian Championship by defeating St. Leonard of the Quebec National Soccer League on September 29, 1990, in Toronto, Ontario. The NSL Cup was won by St. Catharines Roma, and North York Strikers secured the Second Division championship.