The 19-year-old aspiring actress shared a photo on Instagram with the 36-year-old actor after spending the day with Stranger Things star Millie Bobby Brown.
Jackson posted a picture early Friday of herself and Culkin smiling and embracing. The pair, who were last seen together in December, had spent the evening hanging out with friends and sharing clips on Instagram Stories.
Culkin is also godfather to Jackson's brothers, 20-year-old Prince Jackson and 15-year-old Blanket Jackson. He was close friends with the siblings' late dad, Michael Jackson, up until the singer's death at age 50 in 2009.
Jackson was spotted with Brown earlier Thursday while filming a mystery project in Los Angeles. She and the 13-year-old actress performed Adele's song "Someone Like You" on the piano and posed together for a photo.
"See you soon, sunshine!" the star wrote.
Jackson guest starred on the Fox series Star in March, and landed a contract with IMG Models the same month. Sources told Entertainment Tonight in January that the teenager is in "a very happy place" as she pursues her creative interests.