Gas venting, more specifically known as natural-gas venting or methane venting, is the intentional and controlled release of gases containing alkane hydrocarbons - predominately methane - into Earth's atmosphere. It is a widely used method for disposal of unwanted gases which are produced during the extraction of coal and crude oil. Such gases may lack value when they are not recyclable into the production process, have no export route to consumer markets, or are surplus to near-term demand. In cases where the gases have value to the producer, substantial amounts may also be vented from the equipment used for gas collection, transport, and distribution.

Gas venting contributes strongly to climate change. Nevertheless, many individual cases are sufficiently small and dispersed to be deemed "safe" with regard to immediate health hazards. Large and concentrated releases are usually abated with gas flares to produce relatively less-harmful carbon dioxide gas. Gas venting and flaring that are performed as routine practices are especially wasteful and may be eliminated in many modern industrial operations, where other low-cost options are available to utilize the gas.

Gas venting is not to be confused with similar types of gas release, such as those from:

Gas venting should also not be confused with "gas seepage" from the earth or oceans - either natural or due to human activity.

Petroleum extraction from oil wells, where acquiring crude oil is the primary and sometimes sole financial objective, is generally accompanied by the extraction of substantial amounts of so-called associated petroleum gas (i.e. a form of raw natural gas). Global statistics from year 2012 show that the majority (58%) of this gas was re-injected for storage and to help maintain well pressure, 27% was sent to consumption markets, and the remaining 15% was vented or flared near the well site.

100 million tons of the vented associated gas was combusted in flares worldwide, equal to about 3-4% of all gas produced from oil and gas wells. The flared gas yielded nearly 350 million tons of CO₂-equivalent emissions of greenhouse gases, contributing about 1% of the 33 billion tons of carbon dioxide (CO₂) released from the burning of all fossil fuels. Flare Gas Recovery Systems (FGRS) are being increasingly implemented as a more economically productive alternative to flaring.

Preferably, all of the unwanted gas would at least be abated in gas flares, but this has not been achieved in practice. For example, the vented volumes from individual wells are sometimes too small and intermittent, and may present other difficulties (e.g. high concentrations of contaminants) that make flaring more technically and economically challenging. Also, gas will continue to effervesce from the crude oil for some time after it is moved into storage tanks at the well site and transported elsewhere. This gas may also be routed to a flare stack, utilized, or designed to escape without mitigation through vents or pressure regulators.

Global tracking estimates from the International Energy Agency (IEA) during year 2019 indicate that an additional 32 million tons of methane were vented without abatement from all petroleum extraction; including onshore conventional oil, offshore oil, unconventional oil, and downstream oil activities. When including the amount released from incomplete gas flares and fugitive emissions, the estimated total is about 37 million tons.