European route E16 is the designation of a main west-east road through Northern Ireland, Scotland, Norway and Sweden, from Derry to Gävle, via Belfast, Glasgow, Edinburgh, previously by ferry to Bergen, Voss, through the Gudvanga Tunnel and the Lærdal Tunnel (the world's longest road tunnel), Lærdal, over Filefjell to Fagernes, Hønefoss, Gardermoen and Kongsvinger.

In Sweden, it passes Malung, Falun and ends in Gävle.

The E16 is the main road between Norway's two largest cities Oslo and Bergen, and the only mountain pass between Oslo and Bergen that is rarely closed due to snowstorms and blizzards (it goes below the tree line).

Outside winter, Route 7 is at least as popular between Oslo and Bergen, since it is shorter.

In 2011, it was decided to extend E16 from the Oslo region eastwards through Kongsvinger, Torsby, Malung, Borlänge to Gävle in Sweden.

A large road construction project was finished in 1992 when a new routing was opened almost all the way between Bergen and Voss.