William Frederick Havemeyer (February 12, 1804 – November 30, 1874) was an American businessman and politician who served three times as mayor of New York City during the 19th century.

He had been left an orphan in childhood, and at the age of fifteen went to London, where he learned the trade of sugar refining, becoming in time the superintendent of the refinery.

Dietrich Wilhelm Hoevemeyer, born in 1725, was a master baker, and a member of the city council of Bückeburg, and also served in the Seven Years' War.

In 1844, Havemeyer entered local politics with the Democratic Party as an elector for James K. Polk and George M. Dallas during the United States presidential election.

He was also friendly with President Martin Van Buren with whom he had corresponded and urged vehemently to emulate Jackson's firmness in the face of popular outcry.

To avoid a conflict, it was determined to send to the Tammany Hall convention three influential men, irrespective of factional feeling.

In this position, he gained many friends in the Democratic Party, and he was recommended to President Polk by a number of influential citizens as eminently fitted for the collectorship of the Port of New York.

With a view to retrieve control of the collectorship, and at the same time not run counter to Havemeyer's growing popularity, they offered him the nomination for the mayoralty.

[2] In 1845, with the support of Tammany Hall, the Democratic Party political machine, Havemeyer was nominated for the office of Mayor of New York, "laying stress on the fact that he was a native New Yorker".

During Havemeyer's administration, the NYPD was organized on May 13, 1845, with the city divided into three districts, with courts, magistrates, clerks, and station houses being set up.

[2] He also became a large stockholder of the Pennsylvania Coal Company and Long Island Rail Road among insurance and other corporate interests.

He was chosen chairman of a noted mass reform meeting held at Cooper Union on September 4, 1871, and his speech on that occasion was one of the most fearless and outspoken of any in its denunciation of the official thieves.

[5] Largely involved in voting the corrupt Tweed administration out of office, Havemeyer was nominated by the Republican Party Convention as a candidate for Mayor of New York on October 1, 1872.