Silurian stromatoporoids from the Oslo Region, southem Norway, have been investigated. Fifteen species belonging to seven genera are described. Among them, one new genus, Oslodictyon, and three new species are proposed: viz. Oslodictyon henningsmoeni, Plectostroma norvegicum, and Stromatopora ringerikensis. The stromatoporoid assemblages are characterized by the Clathrodictyids such as Clathlodictyon and Ecclimadictyon. They are related to those from the Silurian of the Baltic regions such as Gotland and Estonia.