His uncle, Johan Carl, resident in nearby Kelvinside, was a successful merchant in the city, and the Kiep family was prominent and popular in Victorian Glasgow society.
After going to the Gymnasium at the Ilfeld monastery school, Otto Kiep studied law in Germany and London, and graduated from the University of Leipzig with a Dr jur.
Already at this time, his thinking and influence leant towards peace and international understanding, which his biographer and son-in-law Bruce Clements attributes to his liberal upbringing in Scotland.
As Chief of the Reich Press Office, the name Otto Kiep appeared on the list of the group around the men of the failed 20 July Plot to assassinate Adolf Hitler at the Wolf's Lair in East Prussia.
After his arrest in 1944, he was sentenced at the Volksgerichtshof by Roland Freisler to death, and one month after the plot's failure, on 26 August 1944, Otto Kiep was hanged at Plötzensee Prison in Berlin.