An adjustable dog harness has a pair of adjustable length neck straps through which a dog's head passes. A chest strap passes from the neck under the chest and back, to connect with a pair of adjustable length side straps. These side straps pass up from the chest strap to a belly region that may optionally include a belly strap. The side straps are formed into folds, at approximately 45 degree angles, to continue as adjustable length back straps to the adjustable length neck straps. A sliding position ring couples a lead or leash to the side/back strap folds. Buckles are provided in the side straps, and in the optional belly strap, to permit rapid placement and removal of the harness. Through appropriate adjustment of the side and back straps, the harness will alternatively be adapted to function as a pulling, walking, or vehicle harness and for other diverse applications.