Diddy is staring down one of the biggest days of his life -- his prison sentencing -- and now just one day before that goes down, he’s been hit with two new sexual assault lawsuits.

In new court docs -- obtained by TMZ -- Lakeisha Ward and Dejoan Bledsoe ... both represented by attorney Tony Buzbee, who’s unleashed a flurry of cases against the hip-hop mogul -- claim in separate lawsuits they were sexually assaulted by the mogul.

Ward alleges Diddy drugged and sexually assaulted her at a pool party he hosted at his L.A. home in 2018.

Ward says she signed an NDA before entering the party and felt dizzy after just one or two drinks. She claims she was eventually led to a bedroom and laid down as her drowsiness increased ... when she claims Diddy entered, became sexually aggressive, and eventually "climbed on top of her and penetrated her."

Bledsoe says back in 2009, he was just 18 and met Diddy at a small party at the Beverly Hills Plaza Hotel -- where Diddy allegedly enticed him with promises of a recording contract and entry into the music biz.

Bledsoe claims Diddy then drugged and sexually assaulted him throughout the night, as he lapsed in and out of consciousness.

Both of Buzzbee's clients are seeking compensatory and punitive damages for the alleged sexual assaults.

We reached out to a rep for Diddy ... so far, no word back.