|Area||2.39 sq mi (6 km2)|
|- land||2.38 sq mi (6 km2)|
|- water||0.01 sq mi (0 km2)|
|Density||1,611.2 / sq mi (622 / km2)|
|- summer (DST)||CDT (UTC-5)|
Aledo is located at (41.200172, -90.749956).
According to the 2010 census, the city has a total area of 2.39 square miles (6.2 km2), of which 2.38 square miles (6.2 km2) (or 99.58%) is land and 0.01 square miles (0.026 km2) (or 0.42%) is water.
As of the census of 2000, there were 3,613 people, 1,506 households, and 1,016 families residing in the city. The population density was 1,611.2 people per square mile (622.8/km²). There were 1,588 housing units at an average density of 708.1 per square mile (273.7/km²). The racial makeup of the city was 98.34% White, 0.44% African American, 0.11% Native American, 0.30% Asian, 0.19% from other races, and 0.61% from two or more races. Hispanic or Latino of any race were 0.72% of the population.
There were 1,506 households out of which 29.5% had children under the age of 18 living in them, 56.0% were married couples living together, 8.6% had a female householder with no husband present, and 32.5% were non-families. 29.8% of all households were made up of individuals and 17.1% had someone living alone who was 65 years of age or older. The average household size was 2.32 and the average family size was 2.87.
In the city, the population was spread out with 23.4% under the age of 18, 7.1% from 18 to 24, 24.5% from 25 to 44, 24.3% from 45 to 64, and 20.7% who were 65 years of age or older. The median age was 42 years. For every 100 females there were 86.6 males. For every 100 females age 18 and over, there were 83.8 males.
The median income for a household in the city was $33,449, and the median income for a family was $41,934. Males had a median income of $35,233 versus $21,271 for females. The per capita income for the city was $18,498. About 7.1% of families and 8.1% of the population were below the poverty line, including 7.5% of those under age 18 and 9.8% of those age 65 or over.
Notable people 
- Suzy Bogguss, country western singer
- Peaches Graham, catcher for the Cleveland Bronchos, Chicago Cubs, Boston Doves/Rustlers and Philadelphia Phillies
- Frank Lewis Marsh, educator and creationist
- Dewey McDougal, pitcher for the St. Louis Browns
- Judson Welliver, presidential speech writer
Aledo was the home to William & Vashti College (1908–1917) — the campus/buildings were purchased and used by the Roosevelt Military Academy from 1924–1973. The Administration Building was torn down, and the spot was used to construct an assisted living facility. The remaining two buildings (Niles Hall and North Hall) are unused. William & Vashti College was a member of the Illinois Intercollegiate Athletic Conference from 1910–1917.
The High School Mascot used to be the Aledo Green Dragons. School colors were Forest Green and White. The Class of 2006 had 71 students, which is about an average class size.
Aledo High School offers a variety of course curriculum in the sciences, math, literature, social sciences, and the arts. The school has a concert band, jazz band, concert choir, and swing choir. The school also offers a variety of athletics including volleyball, football, both men and women's golf, men and women's basketball, wrestling, track and field, softball, baseball, and cross country. Some extracurricular activities that students can become involved in are scholastic bowl, football, basketball, pon poms, cheerleading, flags, majorettes, and musicals.
From 1915 to 2009, Aledo High School competed in Boy Football. They qualified for the state tournament on 17 occasions since the tournament began in 1974. From 1998 to 2006, Aledo High School has reached the finals of five IHSA boys' football championship tournaments. Of those five, the school won three times.
Aledo School District #201 and Westmer School District #203 have consolidated since the 2009-2010 school year  The consolidation was voted upon by both school boards and was on the ballot for the 2008 election. The measure passed by a 76% margin.
The new consolidated district is Mercer County District #404 and the new mascot adopted by popular vote in early 2009 is the Mercer County Golden Eagles. School colors changed to navy blue and vegas gold. The Class of 2010 had over 120 students, well above the usual average.
Culture and media 
Aledo hosts two annual festivals; the Rhubarb Fest and Antique Days. The Rhubarb festival, which is held every June in the city downtown, offers a variety of rhubarb-related activities, ranging from rhubarb pie sales to free rhubarb seed distributions. The festival additionally offers other crafts and forms of entertainment and music; it has been undertaken every year since 1991. The city of Aledo's Antique Days festivals likewise occur annually in the month of September, and includes a citywide food festival, music from local residents and the high school music departments, and sports competitions among communities in the area.
- "Find a County". National Association of Counties. Retrieved 2011-06-07.
- "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. 2011-02-12. Retrieved 2011-04-23.
- "2010 Census U.S. Gazetteer Files for Places – Illinois". United States Census. Retrieved 2012-05-03.
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.
- "IHSA Boys Football Champions and Runners-Up". Illinois High School Association Statistics. Illinois High School Association. 2006. Retrieved 2008-10-09.
- "Aledo Rhubarb Fest". Aledo Main Street.com. City of Aledo. 2008. Retrieved 2008-09-22.[dead link]
- Blackford, Robert (September 10, 2008). "Aledo prepares for seventh annual Antique Days". The Times-Record. Retrieved 2008-09-22.
- "Station Profile". WRMJ-FM Radio Station. WRMJ 102.3 FM Radio. 2008. Retrieved 2008-09-22.