The Spider-Man: Far from Home actor, 38, was spotted with Cadieu, 23, in New York City on Thursday night. The two smiled and laughed together as they chatted with friends on the sidewalk.
Gyllenhaal wore a light green button-down shirt, dark pants and white sneakers, while Cadieu looked laid back in a black sweater, jeans, multi-colored sneakers, a scarf and glasses.
The two recently stepped out together earlier this week, the day after the closing of his Broadway play Sea Wall/A Life.
They strolled arm-in-arm and later shared a hug as they walked around the city.
The two were first linked in late 2018 when they were spotted on a walk in New York City. They were later seen sticking close a few days after Christmas during a chilly walk in Paris.
While Gyllenhaal may be an Oscar-nominated actor and a Broadway star, he previously told PEOPLE he looks forward to playing the role of a father in the near future.
“I want to continue becoming more of an adult than I already am,” he said in 2017. “Hopefully with a family of my own.”
Gyllenhaal is already an uncle to two girls, whose mother is his older sister Maggie Gyllenhaal.
“My sister has raised two beautiful daughters. They are the most amazing girls,” he said. “It’s fun to send them home with a lot of candy because it was almost like, ‘Enjoy it, Mags!’ A little payback for being the sister who made me perform weird shows at our parents’ dinner parties.”