Ílhavo (Portuguese pronunciation: [ˈiʎɐvu] ^ⓘ), officially the City of Ílhavo (Portuguese: Cidade de Ílhavo), is a city and municipality located in the Aveiro District of central Portugal. The population in 2021 was 39,239, in an area of 73.48 km².

The Municipality of Ílhavo includes four parishes and two cities: Gafanha da Nazaré and Ílhavo proper.

Several stories have been gathered as part of the history of this city:

Traditionally, the local women — As ilhavenses — are famous for their beauty.^{[citation needed]} It is claimed the city was founded by Greek colonists around 400 BC to whom the beauty of "ilhavenses" women is attributed, but others state that the Phoenician settlers are the ones responsible for that.

Ílhavo's nickname is "the city of the lamp" (a cidade da lâmpada). According to legend, one Sunday during Mass, one of the most important relics of the church (an oil lamp) was stolen in front of everybody and was never found. The myth continued given Ílhavo that nickname.

Administratively, the municipality is divided into four civil parishes (freguesias):

There are two cities in the municipality.

The municipality day is Easter Monday.