The 28-year-old Hunger Games star sparked engagement rumours after she was seen wearing a ring on a night out with Mr Maroney, a 34-year-old art dealer, in New York last weekend.
Lawrence, one of the world's highest-paid actresses, won the best actress Oscar for starring in 2012's Silver Linings Playbook film.
No wedding date has yet been announced.
The couple reportedly met when they were introduced last year by Lawrence's long-time friend Laura Simpson, who accompanied her to the Oscars film awards in 2014, US media report.
Lawrence, who starred in 2018's Russian-themed spy thriller Red Sparrow, told Entertainment Tonight ahead of the film's release that she planned to take time off from acting to focus on political activism.