Frank D. O'Connor was born on December 20, 1909 on the West Side of Manhattan to Irish immigrant parents, James and Margaret O'Connor. The following year, the family moved to Elmhurst, Queens, where O'Connor grew up. After graduating from Newtown High School, he attended Niagara University, where he helped to pay his way by working as a lifeguard. In 1934, he earned his law degree from Brooklyn Law School. During World War II, he joined the Coast Guard, where he served as a legal officer in Alaska.

O’Connor was elected to a seat in the New York State Senate in 1948 as a Democrat representing Queens. He was re-elected in 1950, but lost his seat in the Eisenhower landslide of 1952. He regained his State Senate seat in 1954. In 1953, he defended Christopher Balestrero, a musician who had been wrongfully accused of two holdups in Queens. Three years later, Alfred Hitchcock directed "The Wrong Man," a movie based on the case.

In 1957, Frank O'Connor was elected District Attorney of Queens County, a position he held until 1966. In 1964, O'Connor’s office successfully prosecuted Winston Moseley, who killed Kitty Genovese, the young woman whose cries for help went unheeded by at least 38 residents.

In 1966, he won election as President of the City Council and in that same year ran for governor against Republican Nelson A. Rockefeller. Although O'Connor lost the election by almost 400,000 votes, this was the smallest victory margin in Governor Rockefeller's four campaigns. After that election, Rockefeller said of his Democratic opponent, "He never even told one lie about me."

O'Connor was elected to a seat on the State Supreme Court in Queens County in 1968, and served until 1976, when Governor Hugh L. Carey appointed him to the Appellate Division. He retired in 1986.

Judge O’Connor died at Booth Memorial Hospital in Flushing, Queens on December 2, 1992 from head injuries he suffered when he fell down a flight of stairs at his home.

Frank D. O'Connor was born on December 20, 1909 on the West Side of Manhattan to Irish immigrant parents, James and Margaret O'Connor. The following year, the family moved to Elmhurst, Queens, where O'Connor grew up. After graduating from Newtown High School, he attended Niagara University, where he helped to pay his way by working as a lifeguard. In 1934, he earned his law degree from Brooklyn Law School. During World War II, he joined the Coast Guard, where he served as a legal officer in Alaska.

O’Connor was elected to a seat in the New York State Senate in 1948 as a Democrat representing Queens. He was re-elected in 1950, but lost his seat in the Eisenhower landslide of 1952. He regained his State Senate seat in 1954. In 1953, he defended Christopher Balestrero, a musician who had been wrongfully accused of two holdups in Queens. Three years later, Alfred Hitchcock directed "The Wrong Man," a movie based on the case.

In 1957, Frank O'Connor was elected District Attorney of Queens County, a position he held until 1966. In 1964, O'Connor’s office successfully prosecuted Winston Moseley, who killed Kitty Genovese, the young woman whose cries for help went unheeded by at least 38 residents.

In 1966, he won election as President of the City Council and in that same year ran for governor against Republican Nelson A. Rockefeller. Although O'Connor lost the election by almost 400,000 votes, this was the smallest victory margin in Governor Rockefeller's four campaigns. After that election, Rockefeller said of his Democratic opponent, "He never even told one lie about me."

O'Connor was elected to a seat on the State Supreme Court in Queens County in 1968, and served until 1976, when Governor Hugh L. Carey appointed him to the Appellate Division. He retired in 1986.

Judge O’Connor died at Booth Memorial Hospital in Flushing, Queens on December 2, 1992 from head injuries he suffered when he fell down a flight of stairs at his home.