An infant stroller apparatus includes a first and a second leg segment, a handle segment and a backrest frame. The first and second leg segments are respectively affixed with a first and a second coupling member that are connected with each other. The handle segment is affixed with a third coupling member that is connected with the first coupling member. The backrest frame is connected with the second leg segment. A latch assembled with the second coupling member is movable to engage with the third coupling member to lock the handle segment and the first and second leg segments in an unfolded state. A release actuator operatively connected with the latch is pivotally connected with the second leg segment adjacent to the pivot axis of the backrest frame. The release actuator is rotatable to cause the latch to disengage from the third coupling member for allowing folding of the infant stroller apparatus.