Elias Christian Thorvald Krak (12 June 1830 - 6 November 1908) was a Danish road engineer who headed the Department of Physical Planning (stadskonduktør) for 40 years in the City of Copenhagen and published the first City directory for Copenhagen.

In 1858, just 28 years old, he was appointed to stadskonduktør in Copenhagen and resigned from the army with status of captain.

[3] In 1862, Krak was awarded a license to publish a city directory for the Greater Copenhagen area.

He completely reorganized and modernized the publication with inspiration from foreign capitals before publishing his first city directory in 1863.

She was the daughter of senior lieutenant and later Road Inspector Gengeal on Funen Peter Blankenborg Prydz van der Recke (1793–1847) and his wife Caroline Cecilie Petersen (1795–1868).