Edward O'Neill (March 14, 1820 – March 28, 1890) was an American merchant, banker and politician, who served in the Wisconsin State Senate and the State Assembly; and four one-year terms as Mayor of Milwaukee, Wisconsin, as well as nine years on the Milwaukee Board of School Directors, four of them as its president.

He came to the United States at the age of 17 and settled in Manchester, Vermont, where he remained for some time.

He served two one-year terms (1854–1855) in the Assembly and was elected to the State Senate's Sixth District in 1855 for the 1856–1857 sessions.

He would serve as president of its board of managers for ten years, and was repeatedly reappointed by Republican governors on account of his interest in the school.

In 1860, he partnered with John Dahlman and Timothy Dore in opening a large wholesale grocery business, which they continued for ten years.