Standing on the northern shore of Ekeröfjärden, close to a steep slope down to the water, Ekerö kyrka was originally built in the late 1100s as a private church serving the Askanäs (Asknäs) estate. Its spire is a well-known landmark, visible both from the water and the surrounding countryside, and the church remains the main parish church today.
The building has grown considerably from its original romanesque form of nave, narrower chancel and apse. Around 1300 it was extended eastward to roughly its present size, with a sacristy added at the same time. A tower followed in the 1400s, along with vaulting of the roof, and the cross-arms were added around 1680. Restorations since the 1800s are said to have changed the church's appearance only slightly.
Some sources suggest an earlier wooden church may have stood on the same site as far back as the 1000s, though no physical trace of it survives; this claim rests on a runestone at Vaxholm dated to the 1080s, which refers to a man who died on Ekerö and was buried in the churchyard here.
Inside, restoration work in 1933 uncovered fragmentary medieval wall paintings attributed to a painter working close to the style of Albertus Pictor; further conservation took place in the 1970s, though the paintings remain incomplete. The altarpiece, depicting Christ in Gethsemane, is thought to date from the 1600s, while a figure of an apostle above the pulpit, from the 1470s, is believed to have come from an altar shrine once housed in the church. The wooden sculptures flanking the altar are attributed to the workshop of Burchard Precht, and the oldest parts of the font date back to the church's founding in the 1100s.
A notable feature is a Latin runic gravestone, now in the porch or, by another account, in the southern aisle's Lindschöld burial chapel (also known as the Ingeborg Chapel). It commemorates a woman named Ingeborg, daughter of Ermund, believed to have lived at Asknäs; one source speculates she may have been married to a brother of Erik the Holy, though this is far from certain.