Portugal's festival calendar is dense and often deeply local. The big national moments are the summer santos populares — the people's saints festivals in June — which are among the best reasons to visit the country in that month.
Carnaval (February/March) is celebrated with particular exuberance in Torres Vedras and Ovar on the mainland, and in Loulé in the Algarve. Parades, costumes, and general irreverence make it a good time to be anywhere with a town square.
Semana Santa / Holy Week (March/April) is taken seriously in Braga, where processions are among the most atmospheric in Iberia — barefoot penitents, candlelight, and genuine religious intensity.
Festa de Santo António (June 12–13, Lisbon) is Lisbon's biggest street party. The Alfama and surrounding neighborhoods fill with sardine smoke, cheap wine, paper decorations, and dancing until dawn. Street weddings (casamentos de Santo António) are a tradition: couples apply to marry on the saint's day in a collective ceremony.
Festa de São João (June 23–24, Porto) is Porto's answer — and if anything livelier. The tradition involves hitting strangers on the head with squeaky plastic hammers (or, more recently, leeks), grilling sardines everywhere, and launching paper lanterns into the sky over the Douro.
Fantasporto (February, Porto) is an international fantasy and science fiction film festival held in Porto since 1982, one of the more respected genre film festivals in Europe.
Festa dos Tabuleiros (Tomar, every four years) is one of Portugal's most visually striking events: women parade through the town balancing towering structures of bread and flowers on their heads. Next editions follow a four-year cycle.
National Gastronomic Festival (Santarém, October) celebrates regional food from across Portugal, with each day dedicated to a different culinary tradition. One of the better excuses to eat your way through Portuguese cuisine in one place.
Douro harvest (September–October) isn't a single festival but a season: the grape harvest in the Douro Valley brings festivals, port lodge events, and the chance to see the terraced vineyards at their most beautiful.