Gustav Ludolf Martens (20 October 1818 – 7 January 1882) was a German architect and state master builder of Kiel. Martens worked in Denmark during the 1850s century and influenced architecture in and around Aarhus in Jutland. Martens was born in the Hanseatic city of Wismar where he was trained as a carpenter. In 1837 he attended the Royal Danish Academy of Fine Arts in Copenhagen and obtained a degree in architecture in 1838. Martens moved back to Germany where he studied in Vienna and Munich before he eventually found work in Hamburg where he worked for a number of years. In the 1850s Martens moved to Kiel.