Riders to the Sea is set in the Aran Islands of Ireland in the early 1900s. Despite being colonized by the English in the 1500s, these small islands off the coast of mainland Ireland remained fairly isolated, leading to the preservation of certain aspects of traditional Irish culture. This comes across in the play through the frequent use of Gaelic words mixed in with English, as well as in the various pagan rites and rituals that appear in the play.
Synge was a key actor in the Irish Literary Revival—a movement led by Irish writers who wanted to tell stories involving traditional Irish folklore and mythologies—and his choice to set his play in this secluded part of Ireland was intentional. He spent years on the Aran Islands in order to understand this unique traditional culture, ultimately reproducing it in Riders to the Sea to capture the ways that Aran Islands residents relate to spirituality and the sea.
The island setting is extremely important as the sea itself almost becomes a character in the play. For the people of the Aran Islands (in both real life and in the play), the sea is simultaneously what allows them to prosper (via fishing and trade) and what mercilessly takes their lives. It becomes clear over the course of the play that, while the characters worship an all-powerful God, as island dwellers they view the sea as even more powerful.