Féchy has an area, as of 2009, of 2.7 square kilometers (1.0 sq mi).
 Of this area, 1.9 km² (0.73 sq mi) or 70.4% is used for agricultural purposes, while 0.18 km² (0.069 sq mi) or 6.7% is forested.
  Of the rest of the land, 0.62 km² (0.24 sq mi) or 23.0% is settled (buildings or roads), 0.01 km² (2.5 acres) or 0.4% is either rivers or lakes.

Of the built up area, housing and buildings made up 12.2% and transportation infrastructure made up 7.8%.
 Power and water infrastructure as well as other special developed areas made up 2.6% of the area  Out of the forested land, 5.2% of the total land area is heavily forested and 1.5% is covered with orchards or small clusters of trees.
 Of the agricultural land, 27.8% is used for growing crops and 3.0% is pastures, while 39.6% is used for orchards or vine crops.
 All the water in the municipality is flowing water.

The municipality was part of the Aubonne District until it was dissolved on 31 August 2006, and Féchy became part of the new district of Morges.

The municipality consists of two settlement areas on both sides of road known as Vy d'Etraz, which runs between Nyon and Aubonne.
 It consists of the village of Féchy and the hamlets of La Crausaz, Le Saugey and Féchy-Dessus and the new development of Les Cassivettes.
Féchy has an area, as of 2009, of 2.7 square kilometers (1.0 sq mi).  Of this area, 1.9 km² (0.73 sq mi) or 70.4% is used for agricultural purposes, while 0.18 km² (0.069 sq mi) or 6.7% is forested.   Of the rest of the land, 0.62 km² (0.24 sq mi) or 23.0% is settled (buildings or roads), 0.01 km² (2.5 acres) or 0.4% is either rivers or lakes.
Of the built up area, housing and buildings made up 12.2% and transportation infrastructure made up 7.8%.  Power and water infrastructure as well as other special developed areas made up 2.6% of the area  Out of the forested land, 5.2% of the total land area is heavily forested and 1.5% is covered with orchards or small clusters of trees.  Of the agricultural land, 27.8% is used for growing crops and 3.0% is pastures, while 39.6% is used for orchards or vine crops.  All the water in the municipality is flowing water.
The municipality was part of the Aubonne District until it was dissolved on 31 August 2006, and Féchy became part of the new district of Morges.
The municipality consists of two settlement areas on both sides of road known as Vy d'Etraz, which runs between Nyon and Aubonne.  It consists of the village of Féchy and the hamlets of La Crausaz, Le Saugey and Féchy-Dessus and the new development of Les Cassivettes.
Féchy