Londrina (Portuguese pronunciation: [lõˈdɾĩnɐ], literally "Little London") is a city located in the north of the state of Paraná, South Region, Brazil, and is 388 km (241 miles) away from the state capital, Curitiba. It is the second largest city in the state and fourth largest in the southern region of the country, with 555,965 inhabitants in the whole municipality (2022).

Londrina was originally explored by British settlers, and then officially established in 1930 by a small group of Italian, Japanese and German settlers. It rapidly became the commercial, political, and cultural centre of the state's northern pioneer zone. Its universities include the Universidade Estadual de Londrina (Londrina State University) and the Universidade Tecnológica Federal do Paraná (Federal University of Technology – Paraná).

The city was named after British entrepreneurs who launched railroad stations in the region to ease the transportation of coffee grains from northern Paraná and southern São Paulo states to the port of Santos. The word Londrina pays homage to the British capital (Londres in Portuguese), since a London cotton company, Paraná Plantations Limited, made the original investment to settle in this area.

The city is located in the north of the state of Paraná, and is 388 km (241 miles) away from the state capital, Curitiba.

According to the Köppen-Geiger climate classification system, the city of Londrina has a humid subtropical climate (Cfa) influenced by the Atlantic Forest biome. Average annual precipitation is 1,622.6 mm (63.9 in). Mean average annual temperature is 20.62 °C (69 °F).

Agriculture continues to be Londrina's major economic activity, although its importance has diminished in recent years. Agricultural activity was diversified beyond coffee, and today corn, wheat, cotton, horticulture, beans, peanuts, rice, sugar cane, soy bean, and fruit plantations thrive due to the rich Northern Paraná/South Western São Paulo State "terra roxa/vermelha" crimson soil. Although the city has increased its industrial park by adding weaving, textiles and agricultural factories, Londrina's main wealth continues to be agricultural production. Today, Londrina is also known for its commerce and service sectors. Moreover, real estate is another growing sector that has generated jobs and boosted even more the size of this city in Paraná.

It possesses one of the largest universities in the country, the Londrina State University, as well as several private colleges.

The city is served by Londrina – Governador José Richa Airport.