He tried to make a splash.

A suited-up Mayor Zohran Mamdani leapt into an East Harlem pool Saturday morning to officially kick off the Big Apple’s summer pool season.

Hizzoner joined dozens of young swimmers for the plunge, fulfilling a promise he made to continue the obscure custom.

Mamdani even kept his black socks on as he made his half-hearted cannonball.

The socialist mayor had committed to the leap after being pressed by Katie Honan of The City Reporter, who asked if he would reignite the practice of mayors jumping into pools on opening day.

Mayor Michael Bloomberg was the last to get wet, with Bill de Blasio and Eric Adams tapping out on the tradition.

“I’m gonna be honest, I may do it. I may commit to it,” Mamdani said in March, though he only officially confirmed his leap this week.

The mayor’s jump defied pool rules, however — male swimmers are required to wear bathing suits in the water.