Gustav Johan Fredrik Dietrichson (8 April 1855 – 19 March 1922) was a Norwegian theologian and priest.
[1] Dietrichson was born in the state of Wisconsin.
His parents, Gustav Fredrik Dietrichson (1813–1886) and Pauline Christine Sørine Alette Henriette Preus (1819–1900) were Norwegian immigrants to the United States.
His maternal uncle, Adolph Carl Preus (1814–1878), had immigrated from Norway in 1850.
Preus served as the first President of the Norwegian Synod prior to returning to Norway in 1870 where he served as vicar in Tvedestrand Municipality and Holt Municipality in Aust-Agder until his death.