Kristian Sophus August Erslev (December 28, 1852 – June 20, 1930) was a Danish historian and professor.

From 1881, Erslev became a research fellow at the Gehejme Archives and in 1883 he became professor of history at the University of Copenhagen.

As editor of the Danish Historisk Tidsskrift he also set the standards for solid, factual historical writing.

He looked to other European scientists for inspiration, but never fully solved the problems of objectivity and the influence of "the person behind the pen".

[4] Erslev was inspired in his early days by the idea that historians should strive to create "true science".