An infant carrier apparatus comprises a seat assembly, a backrest assembly including a first and second backrest frame, and a backrest holding mechanism. The first backrest frame includes first side and transverse segments, the second backrest frame includes second side and transverse segments, the first side segment being coupled with the seat assembly via a first pivot point. The backrest holding mechanism can be movably assembled between the first and second transverse segment, and include a latch element movable between a first and second position. The first position of the latch element causes the backrest holding mechanism to be in locking engagement with the first transverse segment to prevent rotation of the backrest assembly relative to the seat assembly, and the second position of the latch element removes the locking engagement of the backrest holding mechanism to permit rotation of the backrest assembly relative to the seat assembly.