Joe Biden won the Democratic presidential Illinois primary, and Donald Trump won the Republican presidential Illinois primary in 2024.

Quick Scoop: Who Won the Illinois Primary?

For the presidential primaries in Illinois in 2024:

  • Joe Biden was the projected winner on the Democratic side.
  • Donald Trump was the projected winner on the Republican side.

These results came at a point when both had already effectively secured their parties’ nominations nationwide, so Illinois served more to confirm the rematch narrative than to change it.

A Bit of Current Context

  • Illinois has continued to hold closely watched primaries for other offices in 2026, including a competitive Democratic U.S. Senate primary, but some of those results are still being updated in live tallies.
  • Media outlets are packaging these elections together in recap segments and live “big board” analysis, which is why you may see several different Illinois primary nights referenced in recent coverage.

If You Meant a Different Race

“Who won the Illinois primary” could also refer to:

  1. A specific year (e.g., 2022 or 2026).
  1. A specific office (governor, Senate, House, or local races).

If you tell me:

  • The year (2022, 2024, or 2026), and
  • Whether you care about president, governor, Senate, or House,

I can narrow it down to the exact winner you’re looking for, within the latest reported results.

TL;DR: For the most commonly asked recent case, in the 2024 Illinois presidential primary, Biden won the Democratic contest and Trump won the Republican contest.

Information gathered from public forums or data available on the internet and portrayed here.