He retired as a Senior Manager in supply and procurement and was employed by Texas Instruments for 35 years.
[3] O'Neill won an unlikely victory by beating Democratic Senate President Joe Montalbano by a 54.3% to 45.7% margin on November 4, 2008.
O'Neill ran an aggressive campaign emphasized on ending political corruption and decreasing taxes and spending.
[5] On November 6, 2012 O'Neill beat Democratic opponent John Cullen and Independent Derek Meiklejohn.
[8][9] In 2013, O'Neill called on his fellow senators to vote against S38, which legalized same-sex marriage in the state, urging them to "vote their conscience[s]” and follow their own “moral compass[es].”[8] in 2016 O'Neill was vocally critical of the Democratic domination of Rhode Island politics, expressing his belief that the current system would reach the same outcomes regardless of Republican opposition.