The Ballot Brief
St Louis County, Missouri

County Council District 3

MissouriSt Louis County › County Council District 3

2 candidates are tracked for County Council District 3 on the November 3, 2026 ballot: Andrew Koenig and Mark Osmack. Candidate information follows official St Louis County election filings; verify with the official election office linked below.

An open seat: Dennis Hancock is vacating it to run for county executive. Neither party has an August 4 contest, so Koenig and Osmack advance to a November 3 matchup. Appears only on District 3 ballots.

Andrew Koenig

Republican

A former state senator and representative who says he passed the state's first income tax cut in nearly a century, and a small business owner raising five children in west county, per a campaign announcement carried by The Missouri Times.

2026 priorities

Mark Osmack

Democratic

A U.S. Army veteran who deployed to Afghanistan during the 2010 to 2011 surge and earned a Bronze Star, per his campaign site. He describes himself as focused on the bottom line, not politics, per his site.

2026 priorities

Source: candidate campaign site, roster verified 2026-08-29.

Campaign site →
Verify this race
Candidate roster from official St Louis County Supervisor of Elections filings, last verified 2026-08-29. Bios and priorities carry their attribution inline.
Cross-check with the official Missouri election office, or see the full St Louis County sample ballot and your exact ballot by address.