Henry John Klutho (1873–1964) was an American architect known for his work in the "Prairie School" style. He helped in the reconstruction of Jacksonville, Florida after the Great Fire of 1901—the largest-ever urban fire in the Southeast—by designing many of the new buildings built after the disaster. This period lasted until the beginning of World War I. Several Jacksonville architects began their careers in the offices of Klutho's firm.
Klutho was born in Breese, Illinois, a small midwest town. He lived there until the age of 16, when he left for St. Louis, Missouri to study business. When he became interested in architecture, he moved to New York City to learn more, and became an architect.
Klutho read about the Great Fire of 1901 in the New York Times and recognized the opportunity of a lifetime. He finished his current projects in New York and quickly moved to Jacksonville. Klutho introduced himself to prominent businessmen and politicians, and within a month, he was commissioned to design the six-story Dyal-Upchurch Building, the first large structure in the barren downtown area. Other projects soon followed, including the new City Hall and private homes.