The Notorious B.I.G.'s Mom Voletta Wallace Dead at 78

The Notorious B.I.G.'s mom, Voletta Wallace, is dead ... TMZ has learned.

Biggie Smalls' mother died Friday morning in Stroudsburg, Pennsylvania ... according to Monroe County Coroner Thomas Yanac.

We're told she was in hospice care and the cause of death here is natural causes.

Voletta carried on Biggie's legacy after his tragic death, overseeing his estate and helping pass down his wealth to his family, including his daughter T'yanna Wallace.

She did a pretty good job running things too ... Biggie's estate was estimated to be worth about $10 million when he died, and it's since ballooned to a now-estimated $160 million.

Voletta celebrated when her son was inducted into the Rock and Roll Hall of Fame, and her Instagram account was mostly dedicated to his achievements ... she posted about his foundation, his streaming numbers, tribute concerts, and pop culture references.

When Biggie's biopic, "Notorious," premiered in 2009 ... Voletta explained why it was important to tell his story on the big screen.

B.I.G. -- real name Christopher Wallace -- was gunned down in L.A. back in 1997 ... following the shooting death of rival rapper Tupac Shakur.

Voletta was 78.