A spray gun 101 has a spray head 150 connected to a body 102 of the spray gun 101 and a reservoir 156 connected to the spray head 150 for supplying liquid to a spray nozzle 153 of the spray head 150. The spray head 150 is arranged so that liquid from the reservoir 156 is delivered to the spray nozzle 153 without passing through the spray gun body 102 in response to actuation of the spray gun 101 via a trigger 105. The spray head 150 is releasably secured and can be detached from the spray gun body 102 and thrown away after use. The reservoir 156 is mounted on the spray head 150 and can be removed and thrown away with the spray head 150 after use.