Nikolauskirche Bad Gastein, Gothic church in Bad Gastein, Austria.

The Nikolauskirche is a Gothic hall church with a square main hall and a polygonal choir section. The northern tower features paired windows and rises to an octagonal spire.

Built in 1389 and first mentioned in 1412, the church became a vicariate in 1622, giving Bad Gastein a resident priest under the pastor of Hofgastein. It served as a parish church until 1639, when the Preimskirche replaced it; being structurally safer, it hosted services during the Preimskirche's closures. It was renovated in 1893, restored from 1950 to 1953, and re-roofed with larch shingles in 2022.

Late Gothic murals cover the walls: the southeast corner shows Christ in a mandorla with the twelve apostles and the Last Judgment, the south wall a Tree of Jesse and a donor figure with the Framynnger coat of arms dated 1517. In the northeast corner are Passion scenes painted around 1470–1480 by the Master of Schöder. The choir frescoes depict the Manna miracle, the Virgin of Mercy, saints and scenes from the life of St Nicholas.

The church stands on a slope at the northern edge of Bad Gastein, beside the road to Badbruck, and is surrounded by a cemetery. The site is reached on foot uphill from the road; the interior is entered through the south portal. The 2022 larch-shingle roof and the restored frescoes are best seen in daylight.

The 1989 restoration of the late Gothic frescoes was initiated by the Rotary Club Bad Gastein for the church's 600th anniversary. The club funded a long-term project and covered a third of the total cost of 3 million schillings.