A source tells ET that Maddox is ringing in his birthday on Friday with his mother and siblings, "and then will be helping Zahara move to Atlanta."
Maddox's sister -- Zahara Jolie-Pitt, 17 -- is headed to Atlanta to begin classes at Spelman College in the fall semester.
While conducting interviews on the red carpet for his new film, Bullet Train, Pitt recently told reporters that he's "so proud" of Zahara.
"She's so smart. She's going to flourish even more at college," he said, according to Vanity Fair. "It's an exciting and beautiful time to find her own way and pursue her interests. I'm so proud."
Zahara is the second of the Jolie-Pitt children to embark on a journey in higher education, following in Maddox's footsteps. Maddox enrolled as a student at Yonsei University in South Korea a few years ago.
"It brings a tear to the eye, yeah," Pitt said of Shiloh and her love for dance and performance, adding that she's "very beautiful."
"I don't know where she got it from. I'm Mr. Two-Left-Feet here," he added with a laugh.
When asked about whether he's hoping his kids stay away from the spotlight or embrace the creative arts, Pitt said he's just hoping they discover the paths that lead them to joy.
"I love when they find their own way, find things they are interested in and flourish," Pitt said of his six children.