The 46-year-old actor - who married Agruma in 2024 - has taken to social media to announce the arrival of their baby girl, with Wilson sharing a photo of Rose Estelle on Instagram.
"Proud to announce the birth of our 2nd daughter Rose Estelle! What a gorgeous blessing to have another little girl!" Wilson wrote.
"Now on May 4th it's now 4 of us! Ramona and I are feeling so incredibly grateful and blessed to grow our family, thank you everyone for all the well wishes."
In response, Agruma replied: "cheers to our family! It's 4 of us now."
Wilson and Agruma have already received congratulatory messages from some of their showbiz pals.
"Wow! The most beautiful," Brittany Snow wrote in the comments section.
Paris Hilton simply said: "Congratulations loves."
The loved-up couple's eldest daughter, Royce, arrived via surrogate in November 2022. And Agruma announced their most recent pregnancy late in 2025.
"The happiest news in our family it will be four of us soon! Baby number 2 is on her way. I love you @rebelwilson," she wrote on Instagram at the time.
Wilson previously admitted she felt compelled to share the news publicly because her eldest daughter couldn't contain her excitement any longer.
"So my one daughter, Royce, she just goes around saying everything to anybody, teachers at school, people in the grocery store," Wilson said on Today With Jenna and Friends.
"She'll be like, 'Yeah, I'm getting a baby sister'. And then people come up, random people go, 'Oh, congratulations on the new baby'.
"So I thought, OK, I better put it out on social media. She's a real chatterbox."