- September 1989: The SLIAC chartered with Blackburn, Fontbonne, Maryville, Parks, Principia and Webster the original members.
- September 1990: The SLIAC's first year gets underway. MacMurray and Westminster join the charter members.
- February 1995: Westminster wins the men's basketball tournament title to earn the SLIAC's first automatic bid to an NCAA Division III national championship event.
- September 1995: Greenville begins its first year as a member of the conference, bringing SLIAC membership to nine schools.
- March 1996: MacMurray wins the women's basketball tournament title to earn the conference's first automatic bid to an NCAA Division III women's national championship event.
- April 1996: Parks competes in its final conference event. Parks closed after the 1995-96 year and its academic programs were moved to the Saint Louis University campus.
- November 1996: Blackburn, MacMurray, and Westminster share the first-ever SLIAC football title.
- September 1999: The SLIAC begins its tenth year of operation.
- November 1999: The fourth and final (until 2008) conference football title is awarded (six teams needed for conference to sponsor a sport).
- September 2006: Eureka and Lincoln Christian begin play as the ninth and tenth members of the conference.
- March 2007: Huntingdon and LaGrange admitted to the SLIAC as affiliate members in the sport of football. The SLIAC announces football will return in the fall of 2008 after a nine-year hiatus.
- May 2007: William Wolper hired as the Conference's first full-time Commissioner (officially started in July).
- November 2007: With the completion of the fall season, Lincoln Christian departs the SLIAC.
- September 2008: Football begins play as the 13th conference sport after a nine-year hiatus.
- September 2008: Spalding University admitted to the SLIAC to begin play during the 2009-10 academic year.
- April 2009: The SLIAC announced it would cease its sponsorship of football; five football-playing schools join the Upper Midwest Athletic Conference (UMAC) as associate members for the sport. Huntingdon and LaGrange end football affiliation with the conference.[2]
- June 2010: University of Dallas admitted to the SLIAC as an affiliate member in the sports of men's golf, men's and women's cross country.
- September 2010: University of Dallas is accepted as a full member into the Southern Collegiate Athletic Conference (SCAC) and drops its affiliate membership with the SLIAC after the spring men's golf season.
- December 2011: Iowa Wesleyan College admitted to the SLIAC as a full member to begin play during the 2013-14 academic year.