Kim Guadagno, a Republican, found that Lewis, a Democrat, has not been a resident of the state for at least four years as required by the state constitution, The New York Times reported. Lewis voted in California as recently as 2009, although he has owned a house in New Jersey since 2007 and spent time in the state.
New Jersey holds off-year elections, and the entire state legislature is up for grabs in November. Lewis planned to run in a South Jersey district represented by Dawn Marie Addiego, who was appointed to the seat last year to fill a vacancy.
Lewis told The Philadelphia Inquirer that Gov. Chris Christie threatened to cut funding for a youth program if he ran against Addiego.
Democrats can appeal Guadagno's decision. Senate President Stephen Sweeney called her "a partisan elected official following party orders."
Lewis won nine gold medals in track and field in the Olympics.