Tomar, also known in English as Thomar, is a city and a municipality in Santarén district and the Ribatejo historic province of Portugal. The town proper has a population of about 20,000. The municipality population in 2011 was 40,677.

The town of Tomar was born inside the walls of the Convento de Cristo, constructed under the orders of Gualdim de Pais, the fourth grand master of the Knights Templar in the late 12th century.

Tomar is one of Portugal's historical jewels and, more significantly, was the last Templar town to be commissioned for construction. Tomar was especially important in the 15th century when it was a center of Portuguese overseas expansion under Henry the Navigator, the Grand Master of the Order of Christ, successor organization to the Templars in Portugal.

Tomar lies in the most fertile region of Portugal, and one of the most fertile in the whole of the Iberian Peninsula: the Ribatejo ("by the river Tagus") meadows. It is located in the district of Santarém. The predominant treescape is agricultural, consisting of olive, pine and fig trees.

The seat of the municipality is the city of Tomar, which comprises the parishes of Santa Maria dos Olivais and São João Batista. Tomar is also the capital of the Médio Tejo (Mid-Tagus river) region.

The Nabão River cuts across what was the ancient city of Nabantia: its inhabitants are called Nabantinos.