Cyrus Hermann Kotzschmar Curtis (June 18, 1850 – June 7, 1933) was an American publisher of magazines and newspapers, including the Ladies' Home Journal and the Saturday Evening Post.
Born in Portland, Maine, he was forced to leave high school after his first year when his family lost their home in the Great Fire of Portland in 1866. He held a variety of newspaper and advertising jobs in Portland and Boston before establishing his first publication, weekly titled People's Ledger in Boston in 1872. In 1876, he relocated to Philadelphia, Pennsylvania in pursuit of lower printing costs.
His first wife was Louisa Knapp. In 1883 she contributed a one-page supplement to the Tribune and Farmer, a magazine that was published by Curtis. The supplement became an independent publication the following year, with Louisa as the editor of this new magazine. Its original name was The Ladies Home Journal and Practical Housekeeper, but she dropped the last three words in 1886, and it became the Ladies Home Journal. It rapidly became the leading magazine of its type, reaching a circulation of more than one million copies within ten years. Louisa Knapp remained as its editor until she was succeeded by Edward William Bok in 1889. Bok became the son-in-law of Louisa and Cyrus Curtis several years later when he married their daughter, Mary Louise, in 1896. Bok retired from the magazine in 1919, but he made important changes to the magazine that made it even more popular.