Ford, 66, reportedly surprised 44-year-old Flockhart with an engagement ring over Valentine's Day weekend while on a family vacation with adopted son Liam, People reported Saturday.
The actors — who have been dating for seven years — have not yet set a wedding date.
Representatives for the couple couldn't immediately be reached.
Last year, Ford revived his role as Indiana Jones in the latest movie in the series, "Indiana Jones and the Kingdom of the Crystal Skull."
Flockhart, who rose to fame as the star of hit TV show "Ally McBeal," plays a conservative pundit on ABC's "Brothers & Sisters."