Saint-Prex (French pronunciation: [sɛ̃.pʁɛks]) is a municipality in the Swiss canton of Vaud, located in the district of Morges.

In 1973, St-Prex was awarded the Wakker Prize for the development and preservation of its architectural heritage.

The bourg (old town) forms a peninsula extending from the north shore of Lake Geneva.

In recent years the commerce of the town has mostly moved to outer areas.

Saint-Prex has an area, as of 2009[update], of 5.5 square kilometers (2.1 sq mi).

Of the rest of the land, 2.12 km2 (0.82 sq mi) or 38.4% is settled (buildings or roads), 0.02 km2 (4.9 acres) or 0.4% is either rivers or lakes.

It consists of the village of Saint-Prex and the hamlets of Les Iles, Beaufort, Senaugin and Fraidaigue.

The blazon of the municipal coat of arms is Gules, a Fleur-de-lys Argent.

[9] Most of the population (as of 2000[update]) speaks French (3,472 or 82.5%), with German being second most common (212 or 5.0%) and Italian being third (137 or 3.3%).

[8] The age distribution, as of 2009[update], in Saint-Prex is; 629 children or 12.5% of the population are between 0 and 9 years old and 562 teenagers or 11.2% are between 10 and 19.

The entire old city of Saint-Prex is part of the Inventory of Swiss Heritage Sites.

[9] There were 2,321 residents of the municipality who were employed in some capacity, of which females made up 44.6% of the workforce.

The number of jobs in the primary sector was 36, of which 35 were in agriculture and 1 was in fishing or fisheries.

In the tertiary sector; 167 or 23.0% were in wholesale or retail sales or the repair of motor vehicles, 24 or 3.3% were in the movement and storage of goods, 25 or 3.4% were in a hotel or restaurant, 15 or 2.1% were in the information industry, 9 or 1.2% were the insurance or financial industry, 21 or 2.9% were technical professionals or scientists, 137 or 18.8% were in education and 228 or 31.4% were in health care.

Vale, a Brazilian mining company, has a regional office in Saint-Prex.

From the 2000 census[update], 1,638 or 38.9% were Roman Catholic, while 1,521 or 36.1% belonged to the Swiss Reformed Church.

In the Vaud cantonal school system, two years of non-obligatory pre-school are provided by the political districts.

The canton's primary school program requires students to attend for four years.