Carl August Björk (27 July 1837 – 29 October 1916) was a Swedish missionary preacher in the Midwestern United States.

He was the founder of the Mission Friends – some of which later developed into the Evangelical Covenant Church, a Radical Pietistic Christian denomination with Lutheran roots, which he played a key role in founding.

He joined the local Augustana Lutheran congregation early on and preached with the encouragement of pastor Magnus Håkanson.

[3] In 1877, Björk became a pastor of the North Side Mission Church in Chicago, succeeding Sanngren and working there for seventeen years.

His sermons, focusing on "salvation by unmerited grace through Christ alone", were described by his friend and later Covenant president Erik Gustaf Hjerpe, as "gripping and lucid".