Saint-Genis-Pouilly (French pronunciation: [sɛ̃ ʒəni puji]; Arpitan: Sant-Genés-Polyi) is a commune in the Ain department within the Auvergne-Rhône-Alpes region of eastern France.

CERN is the world's largest fundamental physics research laboratory and its presence has largely been responsible for the development of the community of Saint Genis since the middle of the 1960s.

As indicated on the map opposite, the communes surrounding Saint-Genis-Pouilly are: Thoiry, Sergy, Crozet, Chevry, Prévessin-Moëns and Satigny (Swiss).

[5] The meteorological station situated at Geneva International Airport, Cointrin, furnishes measurements of the weather relevant to Saint-Genis-Pouilly.

Saint-Genis-Pouilly, like the whole of the Pays de Gex and the Canton of Geneva, knows the touch of the Joran, the cold wind which descends towards Lac Léman from the high Jura, where it sometimes provokes a storm.

According to a study [7] made in 2002, commissioned by the Department of Agriculture and the Forests of Ain, Saint-Genis-Pouilly is classed in a zone at risk from flooding.

That part of the Allondon valley which is found within the territory of the commune constitutes a natural zone with interesting ecology, fauna and flora (ZNIEFF type I).

[15] A diary of 1698 mentions a certain Balthazard as a noble of Prengin, in the Pays de Gex (perhaps this is the name given during this epoque to the current hamlet of Pregnin).

[18] The name of Saint-Genis, as in the case of Saint-Genis-Laval, probably comes from Saint Genest, a Roman comedian from the second half of the 3rd century, martyred under Diocletian.

[19] The Roman colony Colonia Iulia Equestris founded by Julius Caesar between 50 and 45 BC extended as far as Thoiry and included the territory which was to become Saint-Genis-Pouilly.

[20]: 67 Cassini's map of 18th century Geneva, based on measurements taken by Calon de Felcourt between 1759 and 1761, shows the town of Pouilly and the hamlets of Pregnin and Flies.

A few (albeit rather rare) events in the history of the commune : It was the extension within France of CERN (the European Organization for Nuclear Research) in the middle of the 1960s which made Saint-Genis-Pouilly the little town ("coquette")[26] that it is today.

In addition to CERN, the proximity of Switzerland and the international organisations headquartered in Geneva explains why a significant proportion of the population of the commune are foreigners.

[33] The majority of the population in the Pays de Gex, Ain, the Rhône-Alpes region, and mainland France are owner-occupiers of their homes.

[36] For the referendum on the Treaty establishing a constitution for Europe, on 29 May 2005, 1,865 of the 3,089 electors who voted and the 1,838 (suffrages) expressed on this occasion which were reported in the following manner: 1,087 Yes (59.14%) and 751 No (40.86%).

For the referendum on the Treaty of Maastricht, on 20 September 1992, 1,814 of the2,576 electors who voted and the 1,774 (suffrages) expressed on this occasion which were reported in the following manner: 1,186 Yes (66.85%) and 588 No (33.15%).

The church of Saint Pierre at Pouilly (porch and choir from the 13th century) is without doubt the most well known element of religious architecture in the commune.

Pregn'Art is an annual weekend event in the course of which several local artists exhibit their work in the gardens of the inhabitants of the hamlet of Pregnin.

The principal fete of the commune is the Bird Festival "La fête de l'oiseau", which took place between 4 and 7 June on 2010.

Saint-Genis-Pouilly benefits, as do all the other communes in the Pays de Gex, from the specific laws implementing the free trade zone.