The PFL 4 mixed martial arts event for the 2019 season of the Professional Fighters League was held on July 11, 2019, at the Ocean Resort Casino in Atlantic City, New Jersey. This was the fourth regular season event of 2019 and include fights in the welterweight and women's lightweight divisions.

Invicta FC 48: Tennant vs. Rubin was a mixed martial arts event headlined by Taneisha Tennant defending her bantamweight championship against Olga Rubin. The co-main event was set to feature Katharina Lehner fighting Talita Bernardo, but Lehner withdrew from the bout and was replaced by Yana Gadelha. Mallory Martin pulled out of her fight against Kyra Batara and was replaced by Valesca Machado.