Implementations of golf club head covers may include a body portion defining an internal cavity for receiving a golf club head, the internal cavity exposed at an opening in the body portion, a flap coupled to the body portion and configured to cover the opening of the body portion, a guide strip coupled to the flap, a strap holder configured to move along the guide strip slidably coupled to the guide strip, and a strap coupled at an end of the strap holder, wherein the strap is configured to secure the flap over the opening through coupling to a front face of the body portion.