San Giorgio in Alga (English: "St. George in the seaweed"[1]) is an island of the Venetian lagoon, northern Italy, lying between the Giudecca and Fusina (a frazione of Venice on the coast, near Marghera).

In 1404, Ludovico Barbo, the commendatory prior of a monastery of Augustinian friars on the island which was almost abandoned, gave the monastery to a small community of canons leading a contemplative life.

Soon they became the head of a congregation known as the Canons Regular of San Giorgio in Alga.

[2] One of Barbo's reforms was to allow the canons to sleep in separate cells to provide more opportunity for solitary prayer.

The island was used in 1944 as a secret base for German military personnel training as free-diving frogmen to master mine laying against Allied ships.