Frits Schlegel (4 May 1896 – 5 March 1965) was a Functionalist Danish architect active during the transition from traditional craftsmanship to industrialized construction methods in the building industry. He was among the first architects in Denmark to experiment with poured-in-place concrete. Schlegel was born in Frederiksberg, Copenhagen. He completed an apprenticeship as a mason in 1915 and studied at the Royal Danish Academy of Fine Arts from 1916 to 1923, winning the small gold medal in 1924 (for a stadium design) and the large gold medal in 1927 (for a university in Aarhus). After working at the offices of Edward Thomsen (1916–34) and Gudmund Nyeland Brandt (from 1920), Schlegel set up his own office in 1934 which he operated until his death in 1965.
His early works show inspiration from the French architect Auguste Perret. His most important works include Tivoli Concert Hall in the Tivoli Gardens, Mariebjerg Chapel and Overformynderiet in Copenhagen. Particularly in the 1930s, Schlegel also designed a number of furniture lines with inspiration from the Bauhaus movement.