Lost Nation, Illinois is an unincorporated community and census-designated place (CDP) in Ogle County, Illinois, United States, located south of the city of Oregon. As of the 2010 census, its population was 708. Lost Nation has an area of 2.552 square miles (6.61 km); 2.441 square miles (6.32 km) of this is land, and 0.111 square miles (0.29 km) is water.

Lost Nation has a golf course called "Lost Nation Golf Course".

Historical population

Census	Pop.	Note	%±
2010	708		—
2020	714		0.8%
U.S. Decennial Census

Lost Nation CDP, Illinois – Racial and ethnic composition
Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race.

Race / Ethnicity (NH = Non-Hispanic)	Pop 2010	Pop 2020	% 2010	% 2020
White alone (NH)	683	670	96.47%	93.84%
Black or African American alone (NH)	3	2	0.42%	0.28%
Native American or Alaska Native alone (NH)	4	0	0.56%	0.00%
Asian alone (NH)	0	4	0.00%	0.56%
Pacific Islander alone (NH)	0	0	0.00%	0.00%
Other race alone (NH)	0	4	0.00%	0.56%
Mixed race or Multiracial (NH)	5	14	0.71%	1.96%
Hispanic or Latino (any race)	13	20	1.84%	2.80%
Total	708	714	100.00%	100.00%

41°54′40″N 89°22′00″W / 41.91111°N 89.36667°W / 41.91111; -89.36667