Vendelsö kyrka was inaugurated in September 1967. It is a wooden building of a type known as a 'studio church', designed by the architect Rolf Bergh in collaboration with Olov Hartman, then director of the Sigtuna Foundation. The design is a prefabricated, so-called 'wandering church' with a square plan and a pyramid-shaped roof, with a band of windows running beneath the roofline and further windows set into the corners of the walls.
In 1979 additional premises for children's and youth activities were built onto the church. The whole complex was originally painted dark red, but following a redesign completed in November 2005 it was repainted white, giving the building its present appearance. Some of the ancillary spaces dating from around 1969 were later demolished and replaced with more functional rooms, including a large entrance hall and staff work areas.
Inside, the altar is a simple table of oiled pine, and a wooden crucifix from Oberammergau hangs on the wall behind it. Rather than a traditional pulpit, the church has an ambo — a slanted lectern set on a pillar — standing to the left of the altar. To the right stands the font, a pine stand supporting a hammered copper basin made by Erik Ekstedt. A light-tree and a light-boat, decorative fittings for candles, were made by Elwing Brask.
The original organ was built in 1969 by Grönlunds Orgelbyggeri of Gammelstad, a small mechanical instrument. It was sold in March 2015 to a mission congregation in Bollebygd and replaced with a digital organ.