Key Dates for 2026 Illinois Primary Election

Chicago-area voters should mark their calendars for important voting deadlines and early voting periods.

Published on Feb. 28, 2026

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The 2026 Illinois Primary Election is fast approaching, and Chicago-area residents will want to be aware of several key dates and deadlines. Early voting begins on March 2 and continues through March 16, with polling places open on Election Day, March 17. Voters casting mail-in ballots must ensure their ballot is postmarked by Election Day and received within 14 days after. Recent changes to USPS postmark policies mean voters should submit mail-in ballots as early as possible to avoid issues.

Why it matters

The 2026 Primary Election in Illinois will feature important races for congressional and gubernatorial seats, as well as local referendums. Ensuring voters are aware of key dates and deadlines is crucial for maximizing voter participation and the integrity of the electoral process.

The details

Early voting for the 2026 Illinois Primary Election will begin on Sunday, March 2, with polling places open in all 50 wards of Chicago and across suburban counties. Early voting will continue through March 16, though many sites will also be open on Election Day, March 17. For voters casting mail-in ballots, those ballots must be postmarked on or before Election Day and received no later than 14 days after. However, a recent change to USPS postmark policies means the postmark date may not reflect the date the ballot was received, so election officials are urging voters to submit mail-in ballots as early as possible to avoid any issues.

  • Early voting begins on Sunday, March 2, 2026.
  • Early voting continues through March 16, 2026.
  • Election Day is Tuesday, March 17, 2026.
  • Mail-in ballots must be postmarked by March 17, 2026 and received within 14 days after.

The players

Monica Gordon

Cook County Clerk, who warned that the USPS postmark policy change could impact elections.

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What they’re saying

“'While this change has been described as minor, its potential impact on elections is anything but,'”

— Monica Gordon, Cook County Clerk (nbcchicago.com)

What’s next

Election officials are urging voters to submit mail-in ballots as early as possible to avoid any issues with the new USPS postmark policy.

The takeaway

With key races and referendums on the ballot, Chicago-area residents should mark their calendars with the important dates and deadlines for the 2026 Illinois Primary Election to ensure their voices are heard.