Kadoorie Synagogue, Modern synagogue in Massarelos, Portugal.

Kadoorie Synagogue is an Art Deco synagogue on Rua Guerra Junqueiro in Porto, completed in 1938 and the largest in the Iberian Peninsula. Its light-coloured facade has a stepped roofline, a central arched entry recessed behind a round arch, a Star of David above, and the inscription "BEIT HAKNESET KADOORIE". Two smaller arched doorways with dark doors flank the entrance, and tall narrow arched windows sit high on the wall.

The Comunidade Israelita do Porto was registered in 1923 by Captain Artur Barros Basto, a convert to Judaism, and the first stone was laid in late 1929 on land bought to convert Marranos of Trás-os-Montes and Beiras. Work stalled until 1933; the Kadoorie family, honouring Laura Kadoorie, funded much of the building, inaugurated in 1938. Barros Basto was expelled from the army in 1937.

The name combines Kadoorie, honouring the family of Laura Kadoorie, with Mekor Haim, Hebrew for 'source of life', chosen by founder Artur Barros Basto. The interior is decorated with Hebrew passages from the Torah and Moroccan-Sephardic ornament. Members come from over thirty countries, and the community runs a Jewish museum and interfaith projects with the Porto diocese and Muslim community.

The synagogue stands on an elevated, fenced platform between Rua Guerra Junqueiro and Rua João Martins Branco in Campo Alegre, north of the city centre. The Jewish Museum of Porto opened on the site in 2015, and the building has been open to the public since 2012. Visits are arranged with the Comunidade Israelita do Porto, so confirm access before travelling.

During World War II, the building served as a stopping point for Jewish refugees seeking safety overseas. Portugal served as a transit route for people fleeing persecution during that period.