Nicoya is a district and head city of the Nicoya canton, in the Guanacaste province of Costa Rica, located on the Nicoya Peninsula. It is one of the country's most important tourist zones; it serves as a transport hub to Guanacaste's beaches and national parks.

Nicoya has an area of 310.61 km² and an elevation of 123 metres.

For the 2011 census, Nicoya had a population of 24,833 inhabitants.

In early 2006, a group of researchers led by adventure writer Dan Buettner and supported by National Geographic Magazine, the National Institute on Aging, and Allianz Healthcare, designated Nicoya as a Blue Zone. This designation is granted to global regions that are characterized by the longest life expectancies. Among the ideal Nicoyan lifestyle characteristics cited by the research were the water's high calcium and magnesium content, intense daily physical activity, year-long fruit consumption, and close inter-generational relationships.

As of 1850, Nicoya harvested pearls for export.

The district is covered by the following road routes:

Route 21 is the main road serving Nicoya, connecting the city with Liberia (76 km, north-bound). On the opposite way, Route 21 also connects Nicoya to the rest of Nicoya Peninsula, including Pueblo Viejo (exit to Route 18, and then connecting to Route 1), on the main way to San José (204 km vía Route 1).

Nicoya has also an airport for domestic flights with no current scheduled services.