A gooseneck (or goose neck) is a 180° pipe fitting at the top of a vertical pipe that prevents entry of water. Common implementations of goosenecks are ventilator piping or ducting for bathroom and kitchen exhaust fans, ship holds, landfill methane vent pipes, or any other piping implementation exposed to the weather where water ingress would be undesired.

Gooseneck may also refer to a style of kitchen or bathroom faucet with a long vertical pipe terminating in a 180° bend.

The name gooseneck comes from the similarity of the pipe fitting to the bend in a goose's neck.[1]

To avoid hydrocarbon accumulation, a thermosiphon should be installed at the low point of the gooseneck.[citation needed]