Fátima is a city located in the municipality of Ourém within the Santarém district of Portugal. Situated in central west Portugal on a plateau approximately 356 metres above sea level, it forms part of the northernmost portion of the Estremadura Limestone Massif. The area is characterized by geological formations such as sinkholes and karst grottoes, sharing similarities with the nearby Serras de Aire e Candeeiros nature park. Administratively, it serves as the largest locality within its homonymous civil parish, which encompasses several other villages and localities.

The civil parish was founded in 1568 when it was annexed by the Collegiate of Ourém, with early inhabitants relying on sheep herding and subsistence farming. The town's identity became permanently linked to Marian apparitions purportedly witnessed by three shepherd children in 1917 at Cova da Iria. Following these events, a small chapel was constructed in 1918, which later became enclosed within the Sanctuary of Our Lady of Fátima. The site gained significant religious prominence after the Catholic Church recognized the apparitions as worthy of belief, leading to the construction of basilicas and associated pilgrimage facilities over subsequent decades.

The city is defined by the Sanctuary of Our Lady of Fátima, a complex containing two minor basilicas and the Chapel of the Apparitions. Key landmarks include a great oak tree near the apparition site, monuments to the Sacred Heart of Jesus, and a segment of the Berlin Wall. The surrounding parish contains localities such as Aljustrel, the birthplace of the visionary children, and Loca do Cabeço, where an angel reportedly appeared in 1916. The urban landscape includes hotels, medical centres for pilgrims, and an electric mini train system connecting the bus station to the religious sites.

Fátima is a world-famous destination for Christian pilgrimage, commemorating the 1917 apparitions of the Virgin Mary. It attracts millions of visitors annually who seek religious devotion or a peaceful lifestyle associated with its spiritual heritage. The city hosts major events linked to the apparition anniversaries and the beatification and canonization of the shepherd children. The atmosphere is shaped by its history as a centre for Marian devotion, often referred to as the City of Peace, drawing international tourists interested in its religious architecture and historical significance.

The city had a population of 13,212 inhabitants as of 2021. Its economy is heavily stimulated by the steady flow of pilgrims and religious tourism, which has driven local development since the construction of the sanctuary. Access is facilitated by frequent buses from Lisbon and Porto, though the nearby railway station is located over 20 km away. Fátima experiences a warm-summer Mediterranean climate with heavy precipitation in autumn and winter, and warm, dry summers, receiving approximately 2,600 hours of annual sunshine.