Jans departs only 12 days before the team opens its 2020 campaign March 1 at the New York Red Bulls.
FC Cincinnati said the 61-year-old former manager of such Dutch clubs as Groningen and Zwolle was leaving as an MLS investigation was progressing after an MLS Players Association complaint of “extremely inappropriate comments.”
“As Major League Soccer’s investigation unfolded and some themes emerged, Ron offered his resignation and we agreed that it was the best course of action for everyone involved with FC Cincinnati,” club president Jeff Berding said in a statement.
“We place the utmost importance on a strong culture within our club, beginning in our locker room, and that every person connected with FC Cincinnati feels valued, respected and trusted.
Jans, who stepped away from his coaching duties on Friday, went 1-5 with four drawn last year for FC Cincinnati after taking over the team last August following the firing of Alan Koch as manager last May.
Yoann Damet, who served as an interim manager last year before Jans was hired, will again serve as an interim head coach while FC Cincinnati general manager Gerard Nijkamp conducts a global search for a new coach.