The Harstad Church is centrally located on a hill slightly to the west of and above the town centre. It was designed by Jan Inge Hovig (1920-1977). The churchyard encircles the building without crowding the church. Due to the layout of the church, the bell tower is easily visible and thus constitutes an important town landmark. The church itself is comprised of three volumes - the nave, parish hall and the bell tower. The nave, with an east facing choir and entrance in the west, is a rectangular structure with a steep saddle roof with small eaves. The parish hall is south facing, and is a low-rise volume with a flat roof. The clock tower with its characteristic roof is situated facing towards the town centre, and has an entrance to the parish hall at the base of the steeple. This church was one of the first working churches that was erected in Norway. A working church has more than mere liturgical functions. Given that the church has a parish hall, parishioner's room and kitchen, it can be used for different activities arranged by the parish.

Different materials were used on the church's exterior, such as slate on the roof and plastered concrete on many of the façades. The overall design of the building structure is vigorous and has sculptural qualities, for example the steeple's arrow-like form.