The Mac Miller Circles Fund Has Raised $700k Since His Death

Mac Miller's still making a difference -- his charity foundation's quickly approaching a million bucks in money raised to help kids in his hometown ... TMZ has learned.

Folks at The Mac Miller Circles Fund tell us ... donations have been pouring in from the late rapper's fans and the total is up to around $350,000. The cash will be used to provide programs and opportunities to underserved youth in the Pittsburgh area, "helping them recognize their full potential through exploration in the arts and community building."

Add that money to proceeds from the October 31 tribute concert for Mac -- which we're told is expected to be another $350k -- and the Circles Fund's hauled in $700k since his death.

As we reported ... the tribute show, "Mac Miller: A Celebration of Life," went down at L.A.'s Greek Theatre and featured performances by artists -- and some of Miller's closest friends -- like Chance the Rapper, Travis Scott, SZA and John Mayer.

We broke the story ... Mac died from an overdose in September. According to the toxicology report, it was the result of "mixed drug toxicity" -- specifically fentanyl and cocaine. The Coroner ruled his death accidental.

Mac was 26.