Gretteåsen is a village in Tønsberg Municipality in Vestfold county, Norway. The village is located about 12 kilometres (7.5 mi) north of the city of Tønsberg, about 7 kilometres (4.3 mi) west of the city of Horten, and about 5 kilometres (3.1 mi) east of the village of Revetal. The European route E18 highway and the Undrumsdal Church are both located about 1 kilometre (0.62 mi) east of the village.

The 0.09-square-kilometre (22-acre) village has a population (2023) of 233 and a population density of 2,697 inhabitants per square kilometre (6,990/sq mi).