Joseph Emmett Haynes (July 31, 1827 – December 6, 1897) was the 20th mayor of Newark, New Jersey from 1884 to 1894.

A Democrat who explicitly appealed to the working class, Haynes is chiefly remembered for securing Newark a safe and abundant water supply, and his mayoralty is seen as a turning point in the prosperity of Newark.

[1][2] Haynes began a $6 million project to obtain water from the Pequannock River instead of the polluted Passaic River, which resulted in a 70% decline in typhoid deaths.

He faced accusations of accepting gifts in exchange for contracts and ballot rigging.

[3] Before he was elected mayor Haynes was principal of Morton Street School.