Sheila J. Simon is an American politician who served as the 46th lieutenant governor of Illinois, from 2011 to 2015. In 2014, she was the Democratic nominee for Illinois State Comptroller, losing to Republican incumbent Judy Baar Topinka. Simon is the daughter of former U.S. Senator Paul Simon, who had previously served as Lieutenant Governor of Illinois (1969–1973), and his first wife, former Illinois State Representative Jeanne Hurley Simon.

The lieutenant governor of Illinois is the second highest executive of the State of Illinois. In Illinois, the lieutenant governor and governor run on a joint ticket and are directly elected by popular vote. Gubernatorial candidates select their running mates when filing for office and appear on the primary election ballot together. When the governor of Illinois becomes unable to discharge the duties of that office, the lieutenant governor becomes acting governor. If the governor dies, resigns or is removed from office, the lieutenant governor becomes governor. Under the Illinois Constitution, the Attorney General is next in line of succession to the Governor's office after the lieutenant governor, but does not succeed to the lieutenant governor's office. From the impeachment of Rod Blagojevich in 2009, until the inauguration of Sheila Simon in 2011, Attorney General Lisa Madigan would have become governor if Pat Quinn had vacated the office. Historically, the lieutenant governor has been from either the Democratic Party or Republican Party. The current lieutenant governor is Democrat Juliana Stratton.