Formed on Valentine's Day of 1973 by Markus Gauss in order to field a London entry for the National Soccer League after the departure of German Canadian FC.

The new ownership of Andrew Crowe and Zoran Kliseric brought an end to London's postseason drought and qualified for the playoffs in 2013.

After four years of ownership both Crowe and Kliseric sold their shares ultimately to former general manager Jasmin Halkic who relegated the club to the Second Division in 2016 in order to serve as a reserve team for Milton SC.

On February 14, 1973, former German Canadian FC vice-president Markus Gauss purchased the club's franchise rights to form London City SC in order to compete in the National Soccer League.

[5] During their first NSL run the Middlesex County team was a regular playoff contender with their best league performance occurring in the 1980 season with a fifth-place finishing.

Their return marked a new philosophical approach in the club's direction by providing an opportunity for young local players to make the transition to the professional level.

Their opponents in the first round were Kosova Albanians with goals coming from Pete Paterson, John Williams, and Howard Buchanan to give London a 3–0 victory in the first series.

Prominent players during the club's CNSL days were Canadian international Frank Sauer, Gert Dörfel, Jurek Gebczynski, Eddie Edgar, Kenrick Emanuel, Nick Bontis, Euclid Bertrand, Anthony Dominique, and Andrew Loague.

[15] The following season the Gauss family handed the head coach responsibilities to Tony Laferrara, where he managed to secure the final playoff berth.

In the preliminary round of the postseason London faced regular season champions Toronto Olympians, but were eliminated from the competition after a 4–1 defeat.

For the next several years London would go through a difficult rebuilding period in order to focus more solely on player development which produced several positive outcomes, but caused the club a playoff drought for twelfth straight seasons.

[26] The 2003 season was a notable one with Harry Gauss once again adding coaching to his list of responsibilities, and appointed Paul Hillman the team captain.

[27] Gauss brought in Albanian imports Gentian Buzali, Albi Mile, Isa Bulku, Ervin Ryta, and former veteran Andrew Loague.

In the wildcard match City faced the Durham Flames, and with goals from Murataj, Loague, and Eris Tafaj the team advanced to the semifinals in a 4–1 victory.

[30] In the semifinals London faced amateur club Kanata, and won the match 2–0 with Erik Elmauer and Phil McDonald contributing the goals.

They also failed to defend their Open Canada Cup title, after a 2–1 loss by last year's finalist the Metro Lions in the wildcard match.

In the Open Canada Cup tournament London successfully challenged for the title by reaching the finals without the use of wildcard match.

[47] After a successful surgery Harry returned to the fold in 2008, but only in the capacity of director-at-large with former player Eddie Edgar appointed as head coach.

The conclusion of the season also marked the end of the Gauss era as the family sold the franchise to Andrew Crowe a Hamilton businessman involved in the recycling business.

[66][67] For 38 years the Gauss family had provided professional soccer to city and developed several players like Tyler Hemming, Josh Wagenaar, David Edgar, Ryan Thomson, Cameron Medwin, Niels Dekker, Paul Munster, Elvir Gigolaj, Haidar Al-Shaïbani, Paul Victor, Semir Mesanovic, and Tom Beattie.

[68] The new ownership brought in significant changes by hiring Manuel Hernandez as the new general manager and Stanislav Zvezdic as the head coach.

[76] London's reserve team returned to the Second Division, and transferred their home venue to the Hellenic Community Centre due to scheduling conflicts with Cove Road.

[79] Dancetovic made history as London clinched a postseason berth, thus ending City's 12 year playoff drought.

[89] In the preliminary round of the postseason City faced the Serbian White Eagles, but suffered an early departure after a 1–0 loss.