Donald Trump took a break from his NYC criminal trial and presidential campaign to celebrate a major milestone ... his son Barron's high school graduation.

The former prez and wife, Melania Trump, were in attendance at the graduation ceremony for Oxbridge Academy in West Palm Beach Friday ... where they watched with pride as their son received his diploma.

Both Donald and his father-in-law, Viktor Knavs, were seen waving at Barron ... who towered above his peers and teachers while wearing a navy blue cap and gown, as well as a red stole.

Barron's college plans have yet to be revealed ... with his father previously saying the teen's choices changed due to the anti-Israel protests going down across U.S. campuses.

Trump was given permission to attend Barron's graduation ... as Judge Juan Merchan had previously called off the trial's proceedings for Friday.

Remember, 45 is standing trial for allegedly falsifying business records in an effort to hide a hush money payment his former lawyer, Michael Cohen, made to porn star Stormy Daniels.

The trial has yet to derail Trump's reelection efforts ... as the businessman is the presumptive Republican nominee for November's presidential election. Trump is set to fly to Minnesota later on Friday ... there he will speak at the GOP's Lincoln-Reagan dinner.

Barron is Trump's youngest child, his only with third wife Melania. He previously welcomed sons Donald Jr. and Eric, as well as daughter Ivanka, with his first wife, the late Ivana Trump. He later had daughter Tiffany with second wife, Marla Maples.

Barron's siblings did not appear to attend his high school graduation.