Hendrick de Keyser (1565-1621) was the architect of Westerkerk. Commissioned by the Amsterdam City Council, the church was built between 1620 and 1631.

It was not the first Protestant church built in Amsterdam, but it was the first biggest in the world for sure. Noorderkerk and Zuiderkerk preceded Westerkerk. Nieuwe Kerk and Oude Kerk were first built for Roman Catholic mass.

Westerkerk was built in the Dutch Renaissance style and in the form of a patriarchal cross. The monument has a rectangular shape, is 48 metres long, 28 metres wide and 27.5 metres high to the wooden barrel vaulting in the nave. Eye-catching is the bright, undimmed sunlight pouring in from every angle via the 36 large windows (the light is not obstructed by any adjacent buildings). This 'light effect' is further enforced by the whitewashed inner walls.

Apart from the large windows, the church is also characterised by grey-white painted ornaments made of natural stone between the white plasterings. Pillars, arcs, joists, pilasters and the main frame of the lower floor are made of Bentheim sandstone painted dark grey. Since the Westerkerk was commissioned by the Amsterdam City Council at the time, the city arms are a recurring theme in the church. Both the nave and the two high side aisle bays are covered with wooden barrel vaults, forming groined vaults at their crossbeams. The remaining low side aisle bays have stone cross-ribbed vaults.