Cook County beats U.S. rate on college degrees, falls behind on high school diplomas

Cook County's adults are more likely than other Americans to hold a college degree. They are also more likely to have left school without a high school diploma.

Of the 3,641,534 adults counted in the county's education estimates, 42.7% have a bachelor's degree or higher, according to Census Bureau survey estimates covering 2020 through 2024. That comes to 1,555,601 people, spread across a county that runs from the Loop out to the north, west and south suburbs.

Statewide, the share is 37.8%. Nationally, it is 35.7%. That puts Cook County 4.9 percentage points ahead of Illinois and 7 percentage points ahead of the U.S., and both gaps sit well beyond the surveys' margins of error.

For readers, the comparison bears on paychecks and on where companies decide to hire. A county where degree-holders are this common offers employers a deeper bench of college-trained workers than the state or the nation does on average.

Measured against other big counties

Chicagoland belongs to a small club of giant metros built around a dominant core county. In Los Angeles County, 36% of adults hold at least a bachelor's degree. In Dallas County, the figure is 35.7%, matching the national rate.

Harris County, home to Houston, comes in at 34.2%, leaving Cook County a full 8.5 percentage points ahead. Wayne County, Detroit's home and Chicago's Great Lakes neighbor, sits at 27.6%.

The other end of the ladder

Degree numbers are only part of the county's story. Some 11.4% of Cook County adults lack a high school diploma, either leaving before their senior year was done or finishing it without graduating. That is 416,621 people.

Nationally, just over 1 in 10 adults lack a diploma, or 10.4%, leaving Cook County 1 percentage point higher, a gap that holds up beyond the margin of error. In Illinois as a whole, the share is 9.5%.

So the county carries more adults at the top of the education ladder and more at the bottom than the nation does. The full mix, including high school graduates and those with some college or an associate's degree, shows how Cook County compares with the state, the nation and its peers.

Chicago's high schools are graduating students at a better clip than they once did. Illinois' on-time graduation rate reached a record high in recent state figures, with Chicago's rate trailing the state's (Chalkbeat). A Chicago Public Schools leader has credited the district's gains since 2001 to making preparation for postsecondary education a major focus (Chalkbeat).

The census figures, though, count every adult living in the county, wherever they went to school, so today's graduation rates move the totals only slowly.

A state goal, missed and reset

Illinois has been chasing a bigger target than bachelor's degrees. In 2009, a statewide education council set a goal for the share of adults holding a high-quality postsecondary credential by 2025 (illinois.gov). The state did not reach it, though postsecondary outcomes continue to improve steadily, according to the advocacy group Advance Illinois (Advance Illinois).

By the state's own count, the share of Illinois adults with a postsecondary degree or credential has risen since 2008 (illinois.gov). That progress has been uneven: one analysis found white adults were far more likely to hold a postsecondary degree than Black or Latino adults (Data Analysis), and that attainment varied widely from one part of Illinois to another (Data Analysis).

Pressure is coming from the job market. Workforce projections indicate that by 2031, most jobs will require education or training beyond high school (illinois.gov).

A deadline is close. Illinois has set Dec. 1, 2026, as the date for a recommendation to the governor on a new attainment goal for postsecondary degrees and credentials (illinois.gov).

About the data

We used the Census Bureau's American Community Survey estimates pooled over 2020 through 2024, from its educational attainment table for adults, for Cook County, Illinois, the U.S. and the core counties of peer metros. We compared shares with at least a bachelor's degree and shares without a high school diploma, and tested differences using a conservative margin of error; the Cook County–U.S. degree gap had a z-score of 20, far above the threshold for statistical significance.

• These are survey estimates pooled over 2020 through 2024, so they carry margins of error and describe that span as a whole rather than any single year.
• County-level figures do not show how attainment differs among Chicago's community areas or between the city and suburban Cook County.
• Comparisons among the peer counties other than Harris County were not tested for statistical significance.

Bachelor's degree or higher: adults whose highest completed schooling is a bachelor's, master's, professional degree or doctorate. Without a high school diploma: adults whose schooling stopped before their senior year of high school or who reached their senior year without receiving a diploma.

Sources

• U.S. Census Bureau, American Community Survey: Educational Attainment for the Population 25 Years and Over (ACS 5-year 2020–2024), latest period 2024; retrieved Oct. 16, 2026. Data