Former NFL star Shawne Merriman has been ordered to pay up in a wrongful death lawsuit involving a Playboy employee who died of an overdose ... TMZ has learned.

According to court docs, obtained by TMZ, a Los Angeles judge entered a $4 million judgment against the former Chargers linebacker and three other defendants earlier this month over the 2017 death of Kimberly Fattorini.

The ruling comes after a jury found Merriman and the other defendants liable last year ... awarding Kimberly's parents, DeAnn and Ferdinand Fattorini, millions in damages.

As TMZ previously reported ... Kimberly's parents sued Merriman in 2019, claiming he drugged and possibly sexually assaulted their daughter before she overdosed following a night of partying.

The lawsuit alleged Kimberly texted a club promoter that Merriman's friend had poured GHB -- commonly known as a date rape drug -- into her drink. Her death was ruled accidental, with alcohol, cocaine and GHB found in her system.

Merriman previously denied any wrongdoing, with his rep telling TMZ the allegations were baseless and police had investigated without finding evidence of wrongdoing on his part.

The newly filed judgment holds Merriman, J.P. Castro and Monica Maass responsible for the $4 million award, along with Elias Wehbe.

The judge also ruled in favor of the nightclub defendants, including The Highlight Room, Tao Group and The Warwick ... meaning they won't have to pay damages to Kimberly's family.

The judgment was officially entered October 5, more than nine years after Kimberly's death.