Thomas Hans Henrik Knoff (January 31, 1699 - January 25, 1765) was a Norwegian army surveyor. Little is known of his education or service, prior to 1730 when he was sent to Iceland by the Danish government to continue and complete Magnús Arason's task of surveying the country. Knoff completed the work in 1734, but made the error of sending a copy of the map to a superior in Norway - an act that outraged his Danish employers. The Danish king stopped short of accusing Knoff with treason - which some had accused him of - but settled for suppressing the maps. These were declared state secrets by the Danish govenment until 1752, when they were provided to Danish scholar Niels Horrebow; through his work the map would be widely disseminated. Knoff's career did not end with the political kerfuffle: we see him engaged in surveys of the border of Norway and Sweden in 1742,