A foldable leisure chair includes a seat unit having a pair of side frames, a pair of armrest members connected pivotally and respectively to the side frames, and a pair of support units. Each support unit includes a coupling seat defining a receiving space therein and having a pivot end part that is connected pivotally to a respective side frame, a seat-engaging rod having an engaging end part that extends telescopically into the receiving space and a connecting end part that is connected pivotally to a corresponding armrest member, and an adjusting mechanism disposed in the receiving space for positioning the seat-engaging rod relative to the coupling seat so as to maintain the corresponding armrest member at a selected one of a plurality of angular positions relative to the respective side frame.