The word "skog" means "forest" in Norwegian, and that is what Rømskog consists of together with the agricultural landscape.

Deep forests that Rømskog shares with the neighbouring municipalities across the border of Sweden.

Slavasshøgda is a hill in Rømskog, and is the highest point in former Østfold county at 336 metres (1,102 ft).

The arms show a pair of silver logging tongs on a blue background.

Since forestry is the main source of income for the municipality, it was considered an appropriate symbol.