Björn Ambrosiani (born 8 March 1928) is a Swedish archaeologist and former civil servant.
He worked at the Swedish History Museum and the Swedish National Heritage Board, as a research director among other positions.
Ambrosiani led a number of excavations at different sites.
In the 1960s he led the excavations at Henriksdalsberget, and from 1969–71 and again from 1990–95 he was responsible for excavations of the Viking-age trading center Birka.
The first project was the first at Birka since that led by Hjalmar Stolpe in the 1870s.