The Ballot Brief
St. Louis County, Missouri

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.

About this race

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.

What this office does

County commissioner. The county board is the county's legislative and, in most states, executive body. Commissioners adopt the county budget and property tax rate, oversee roads, the jail, public health, planning and zoning in unincorporated areas, and appoint or confirm department heads. In counties with an elected county executive or judge, the board's role is mainly the budget and ordinances.

Missouri › St. Louis County › County Council District 3

Andrew Koenig

Republican

Top priorities

  • Reduce what he calls wasteful county spending
  • Tax relief and fiscal accountability
  • Legislative budget-oversight experience

Per his campaign announcement.

Biography

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. No campaign website was found as of September 8, 2026.

Mark Osmack

Democratic

Top priorities

  • Affordable housing, utilities, and essential services
  • Repair and maintain county roads and sidewalks
  • Fiscal responsibility and budget transparency

Per the campaign site.

Biography

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.

Next on your ballotCounty Council District 5

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Voting info and more

Voting info and more
Questions about this race

Who is running for County Council District 3 in 2026?

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.

When is the County Council District 3 election in Missouri?

Election Day is Tuesday, November 3, 2026. Registration deadlines, early voting dates and mail ballot rules for Missouri are on the Missouri election hub at theballotbrief.com.

How do I see my exact St. Louis County ballot?

Enter your ZIP code in the lookup at theballotbrief.com for the statewide and congressional races, or a full street address to add the county, city and district contests for that location.

Verify this race

Candidate roster from official St. Louis County and state election office filings, last verified October 2, 2026. 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.

The rest of your St. Louis County ballot

38 tracked races in St. Louis County, Missouri. Landed here from another county's search? Look up your own ballot below.

Also on your ballot
County Council District 7Missouri House District 66Missouri House District 67See all 38 St. Louis County races
Candidate profiles
Andrew Koenig, full profileMark Osmack, full profileOfficial Missouri election office