According to to director Victor Kossakovsky, the actors gave their firstborn a very special name.
While addressing the audience at a Zurich Film Festival screening of Gunda, which Joaquin produced, the filmmaker announced that Rooney had given birth to her and the 45-year-old actor's first child. Victor reported that the couple named their "beautiful son" River, after Joaquin's late brother.
River, a musician and Oscar-nominated actor known for films like Stand by Me and My Own Private Idaho, died at 23 of a drug overdose outside of the Viper Room in West Hollywood in 1993. Joaquin, who was 19 at the time, was by his side.
News broke that Rooney was pregnant in May. According to Page Six, who was first to report the news, the 35-year-old actress was already six months pregnant at the time, and had been spending her pregnancy quietly quarantining with Joaquin at their home in Los Angeles amid the coronavirus pandemic.
The new parents met while filming 2013's Her, and have been romantically linked since 2016 when they reunited for Mary Magdalene, in which Rooney played the title role while Joaquin played Jesus. They reportedly got engaged last May, but have never commented on it.
Though both actors are known for being extremely private when it comes to their personal lives, Rooney stood by Joaquin's side throughout awards season earlier this year as he picked up both a Golden Globe and an Oscar for his role in Joker.
Watch the video below to revisit Joaquin's emotional speech for his Best Actor win at the Oscars in February, in which he quoted his late brother, River.