The former couple made a public appearance together at the Met Gala earlier this month, as well as back in 2018. It's unclear what exactly led to the split.
It's possible their careers are getting in the way -- Elon's busy running tech empire, which requires lots of travel to Texas and Europe, and Grimes is working in L.A. as a judge on the new FOX show, "Alter Ego."
As we reported ... Grimes gave birth to their baby boy in May 2020.
Elon's adding to a list of famous exes ... which include his first wife, author Justine Wilson, 2 marriages to "Westworld" star Talulah Riley and Johnny Depp's ex, Amber Heard.