The Illinois Attorney General is the highest legal officer of the state of Illinois in the United States. Originally an appointed office, it is now an office filled by election through universal suffrage. Based in Springfield, Illinois, he or she is responsible for providing legal counsel for the various state agencies including the Governor of Illinois and Illinois General Assembly. He or she also conducts all legal affairs pertaining to the state.

The Illinois Attorney General was established on December 3, 1818 based on guidelines adopted by a state constitutional convention. The first person to fulfill the duties of the office was Daniel Pope Cook who only served eleven days. He was later elected to the United States Congress. Cook County was named in his honor.

List of Attorneys General

• Daniel Pope Cook 1819
• William Mears 1819-1821
• Samuel D. Lockwood 1821-1823
• James Turney 1823-1829
• George Forquer 1829-1832
• James Semple 1833-1834
• Ninian W. Edwards 1834-1835
• Jesse B. Thomas, Jr. 1835-1836
• Walter B. Scates 1836-1837
• Usher F. Linder 1837-1838
• George W. Olney 1838-1839
• Wickliffe Kitchell 1839-1840
• Josiah Lamborn 1840-1843
• James A. McDougall 1843-1846
• David B. Campbell 1846-1848
• Robert G. Ingersoll 1867-1869
• Washington Bushnell 1869-1973
• James K. Edsall 1873-1881
• James McCartney 1881-1885
• George Hunt 1885-1893
• Maurice T. Maloney 1893-1897
• Edward C. Akin 1897-1901
• Howland J. Hamlin 1901-1905
• William H. Stead 1905-1913
• Patrick J. Lucy 1913-1917
• Edward J. Brundage 1917-1925
• Oscar E. Carlstrom 1925-1933
• Otto Kerner 1933-1938
• John Edward A. Cassidy 1938-1941
• George F. Barrett 1941-1949
• Ivan A. Elliott 1949-1953
• Latham Castle 1953-1959
• Grenville Beardsley 1959-1960
• William L. Guild 1960-1961
• William G. Clark 1961-1969
• William J. Scott 1969-1980
• Tyrone C. Fahner 1980-1983
• Neil F. Hartigan 1983-1991
• Roland W. Burris 1991-1995
• Jim Ryan 1995-2003
• Lisa Madigan 2003-Present