Ornö has been settled since the Bronze Age, and a chapel is thought to have stood on the island as early as the late 1300s. It was replaced in 1652 by a larger timber church built in a style considered modern for its era, reportedly encouraged by the local landowner Claes Stiernsköld, who hoped to see Ornö established as a parish church in its own right. The church survived the Russian raids of 1719 but was destroyed by fire in 1881, leaving only a brick burial vault, some silver and a chandelier.
The present building, consecrated in 1886, is a wooden church with a nave, a straight-ended chancel and an attached sacristy, with a tower and porch at the west end. Sources differ on the architect: one account names Ludvig Hawerman, while another attributes the design to Per Ulrik Stenhammar. The exterior is clad in white-painted timber panelling, with corrugated metal roofing over the nave and chancel and dark-painted sheet metal on the tower and sacristy roofs.
The brick burial vault built in 1771 by Johan Rosir survived the fire and still stands in the churchyard, a rare physical link to the church's pre-1881 history. Among the furnishings, the octagonal pulpit dates from the time of the current building, set beneath a canopy with a gilded edge.
The font, of marbled wood, and the altarpiece depicting Christ calming the storm were both made by the sculptor Gunnar Söderman, the altarpiece being given to the church in 1930. The church silver includes a communion chalice donated in 1728 and further pieces given by the Rosir family in the following century, remarkably surviving the fire that consumed the earlier building.
The two bells hung originally in a separate bell tower on the hill above the present sexton's house. The larger bell was cast in 1755 by Gerhard Meyer of Stockholm and carries a devotional inscription; the smaller bell was recast in 1859 by Anders Bäckman, also of Stockholm. The organ in the gallery, built in 1962 by Rolf Larsson of Uppsala, is a mechanical instrument of modest size.