According to Us Weekly, the 29-year-old actor told a cashier earlier this month that they were engaged.
Another source claims he told elevator riders the same thing during his #ELEVATE project.
Mia has also been spotted sporting a diamond ring on her finger.
In case you didn’t know, Shia and Mia started dating after they met on the set of Nymphomaniac: Vol. II back in 2012.
Congrats to the happy couple on the exciting news, if it’s true!