Charles Augustus Otis, Sr. (January 30, 1827 – June 28, 1905) was a businessman and the mayor of Cleveland from 1873 until 1874.

Otis was a direct descendant of James Otis Jr. William was a Massachusetts-born manufacturer who worked in Pittsburgh before traveled to Bloomfield, Trumbull County, Ohio, to start a primitive mercantile business and a tavern.

Otis shipped wheat from Ohio to Buffalo, New York en route the Erie Canal.

He manufactured high-quality flour and potash thirty-five miles to Ashtabula River, where it was loaded on a schooner and shipped to Buffalo and New York City.

Otis worked with Dr. Everett and Samuel T. Wellman in the old East Cleveland line.

[3] It was said that Otis' lack of consent for the nomination allowed him to show respectable individuality in his political career.

Gossip and a telegram reached Otis, who hitched a car on an engine; a reception committee, including the mayor, drove to Elyria within thirty-eight minutes.

[6] Mayor Otis argued that the few who could afford to use the Cleveland Water Works "should aid in extending" the service to the rest of the city.

Written on page xxi of the City Documents of 1874, Otis advocated a 33.3% increase in the cost of public waterworks, to fund construction.

[7] Otis left as mayor in the following year due to business reasons.

[2] Otis died at his son's house in 1905, in which his obituary stated that Cleveland lost one of the builders.

Otis was described as a pioneer in the creative industrial enterprises which made the possibility of modern Cleveland.