O'Toole was elected to the Assembly in 1995 and re-elected five times. He served in the Senate from May 2001 to January 2002, and was elected to the Senate again on November 6, 2007. O'Toole serves in the Senate on the Budget and Appropriations Committee and on the Senate State Government Committee. He also serves as the Senate Minority Whip.
In 1995, O'Toole was elected into the General Assembly, the lower house of the New Jersey State Legislature. He was appointed as the Assembly's Deputy Republican Leader from 2004-2008 and was the Assistant Majority Leader from 1998-2001.
O'Toole was elected to the Senate in 2008 (and also from 1996-2001). On Election Day, November 6, 2007, O'Toole defeated Democrat John Zunic to win election to the New Jersey Senate seat in the district, filling the seat vacated by Henry McNamara, a fellow Republican who had represented the district since 1985. O'Toole's running mates David C. Russo and Scott Rumana also won election.
By profession, O'Toole is an attorney with the firm of O'Toole Fernandez Weiner Vanlieu LLC. Senator O'Toole and his wife, Bethany, have two children, Kevin, Jr., and Ryan Marie.
In the state legislature, O'Toole has been a proponent of ethics reform in New Jersey government. He was the original sponsor of legislation creating pension reform in New Jersey. He has sponsored legislation to streamline government, promote education, protect the environment, and lower property taxes.
The Senator has also sponsored legislation for continued funding of full-day kindergarten in the state's 31 Abbott Districts and a law that allows citizens to express their concerns at local council meetings. O'Toole also sponsored a pre-paid college education expense program and legislation that would prohibit campaign contributions from vendors who have government contracts.