Beyonce’s father is a DEADBEAT DAD … at least according to the mother of his 3-year-old son who claims Mathew Knowles has stiffed her out of $24k in child support, TMZ has learned.

According to California State records obtained by TMZ, Mathew missed TWO of the $12k monthly payments he’s been ordered to pay to Alexsandra Wright.

Sources close to Wright says she’s in a financial bind and needs the cash asap — we’re told she’s even had to pull her son from school because she can’t afford to pay for it.

As we’ve reported … the legal battles between Knowles and Wright have been ugly. She claims Knowles sent a threatening email to her in 2011 … warning “there’s a price to pay” for hurting his family.

We reached out to Mathew for comment — so far, no word back.