Olhalvo (Portuguese pronunciation: [oˈʎalvu]) is a parish of the municipality of Alenquer, in western Portugal. Its population in 2011 was 1,907. Olhalvo has an area of 8.30 km².

Significant buildings include:

• Church of "Nossa Senhora da Encarnação", XVII century.
• Convent of Carmelitas Descalços" construction began in 1646, and has been under private ownership since 1941.
• Chapel of "Senhor dos Aflitos", belonged to "Recolhimento de Nossa Senhora da Conceição", in 1663. It was sold to private owners in 1873.
• Cruzeiro
• Fontain

Olhalvo supports many cultural activities; the following groups are active:

• A Philharmonic Band, "Banda da Sociedade Filarmónica Olhalvense", SFO, started activity in 1918

• Folk dance group "O Rancho Folclorico", since 1978, also within SFO
• Folk dance group "A Associação Recreativa da Pocariça", also active in sports
• Samba School, "Escola de Samba de Penafirme da Mata"
• Folk music group "Noses com Vozes", within "Associação Alegres Olhares" related to traditional music.

• Pilgrimage from Olhalvo to Nazaré, "Círio de Olhalvo à Nossa Senhora da Nazaré"–started in the sixteenth century. It occurs each year in September, organized by the inhabitants of Olhalvand, Penafirme da Mata e Pocariça in rotation.
• Singing to the kings "Cantar dos Reis", on the night of 5 January a group of men sings in the streets a theme related to the kings visiting the newborn Jesus. Small paintings are made in the houses wishing a good year to the people.
• Annual festivities occur in September at Olhalvo's main square.

Besides Olhalvo itself:

• Penafirme da Mata
• Casais da Lage
• Cruzeiro
• Pousoa
• Pocariça
• Casal Perdigoto
• Casal Das Surraipas