Österbybruk is a locality situated in Östhammar Municipality, Uppsala County, Sweden with 2,272 inhabitants in 2010.

[1] The Österby works was one of a number mostly in Roslagen, where there were Walloon forges, producing high quality oregrounds iron for export.

The Österby ironproducts were highly valued in England for the production of blister steel by the cementation process.

Österbybruk is one of the most beautiful examples of the remains of the presence and input of Walloon immigrants ('valloner') in Sweden in the 17th century.

More than 1.200 families emigrated in that era to Sweden, where the expertise of Walloon master blacksmiths was highly sought after.