The 1864 United States presidential election in Illinois took place on November 8, 1864, as part of the 1864 United States presidential election. Illinois voters chose 16 representatives, or electors, to the Electoral College, who voted for president and vice president.^[2]

1864 United States presidential election in Illinois

← 1860 November 8, 1864 1868 →
Turnout	20.34% of the total population 0.50 pp[1]
Nominee Abraham Lincoln George B. McClellan Party National Union Democratic Home state Illinois New Jersey Running mate Andrew Johnson George H. Pendleton Electoral vote 16 0 Popular vote 189,512 158,724 Percentage 54.42% 45.58%
County Results Lincoln   50-60%   60-70%   70-80%   80-90% McClellan   50-60%   60-70%   70–80%
President before election Abraham Lincoln Republican Elected President Abraham Lincoln National Union

Illinois was won by the National Union candidate incumbent Republican President Abraham Lincoln of Illinois and his running mate former Senator and Military Governor of Tennessee Andrew Johnson. They defeated the Democratic candidate 4th Commanding General of the United States Army George B. McClellan of New Jersey and his running mate Representative George H. Pendleton of Ohio.^[2] Lincoln won the state by a margin of 8.84%.