Mariager is a small town and market town with 2,537 inhabitants (2020), located on the southern side of Mariager Fjord in Kronjylland. The name means "Mary's Fields" (after the Virgin Mary who named a Bridgettine monastery on the site). The town grew up around this Mariager Monastery in the early 15th century and gained market town rights in 1592. Today, Mariager is characterized by an old urban environment with cobbled streets and many half-timbered houses, which attract tourists from near and far. Mariager is located in Mariagerfjord Municipality and belongs to the North Jutland Region.

The market town is located in hilly terrain sloping down towards the fjord, and is surrounded by many wooded hills, among others. the 110 meter high Hohøj southeast of Mariager itself. The town has a small harbor with pleasure boats and for tourists the scheduled boat Svanen, which in the summer sails from Hobro via Mariager, Hadsund to the mouth of Mariager Fjord. At the harbor there is also a protected swing crane and Denmark's Salt Center, which is a museum for salt extraction, in which you can visit a salt mine and a bathing salt lake with the nickname The Dead Sea.

From the harbor, a veteran railway goes to the small town of Handest 17 kilometers to the west, whose train operation is strongly inspired by the railway traffic between the two towns from 1927 to 1950. Mariager's landmark is the monastery church, Mariager Kirke (from the 15th century), which with its high whitewashed building rises on a hillside high above the city roofs. Mariager also has two Christian continuation schools, Frydensberg and Mariager Continuation School, and a folk high school.