Triathlon Calendar near O'Fallon 2025-2026

Oct

12

Sunday

Families Run for Ovarian Cancer ROC Star 5k

St. Louis | 30 mi from O'Fallon

5 km

Oct

18-19

Sa - Su

The Great St. Louis Halloween Race

St. Louis | 30 mi from O'Fallon

5 km 10 km Half Marathon

Oct

18

Saturday

Trinity Christian Academy 5k

St. Peters | 4 mi from O'Fallon

5 km

Oct

18

Saturday

Minnie Ha Ha 12 Hour Run

Sappington | 26 mi from O'Fallon

Backyard Ultra 6 hr 12 hr

Oct

18

Saturday

Gumbo Flats Pumpkin Run

Chesterfield | 12 mi from O'Fallon

5 km 10 km

Oct

18

Saturday

UMSL 5K Run/Walk

St. Louis | 30 mi from O'Fallon

5 km

Oct

19

Sunday

City Sprint 5k

St. Louis | 30 mi from O'Fallon

5 km

Oct

24

Friday

Moonlight Howl 5K

Ballwin | 16 mi from O'Fallon

5 km

Oct

24

Friday

Wildwood Shivering Shadows 7K

Glencoe | 16 mi from O'Fallon

7 km

Oct

25

Saturday

The Innsbrook Half Marathon

Innsbrook | 19 mi from O'Fallon

6 mi 13 mi

Oct

25

Saturday

Babler Bongo 15K Trail Race

Wildwood | 16 mi from O'Fallon

Trail Run 15 km

Oct

25

Saturday

Hot Cider Hustle - St. Louis

St. Louis | 30 mi from O'Fallon

5 km 10 km

Oct

25

Saturday

Run 4 Impact 5K Trail Run/Walk

St. Louis | 30 mi from O'Fallon

Trail Run 5 km

Oct

26

Sunday

Spooky Sprint- St. Louis

Maryland Heights | 16 mi from O'Fallon

5 km 10 km 13 km

Nov

1

Saturday

Grace's Place Rock the Block Race

Washington | 24 mi from O'Fallon

17 mi

Nov

1-2

Sa - Su

The Skippo Trail Race

Manchester | 18 mi from O'Fallon

Trail Run 10 km Half Marathon 30 km 40 km

Nov

1

Saturday

Coyote Crawl 5k and Head for the Hills 10k

St. Louis | 30 mi from O'Fallon

5 km 10 km

Nov

1

Saturday

Run S'more for Hope

St. Peters | 4 mi from O'Fallon

5 km

Nov

1

Saturday

Junior League of Saint Louis Cinnamon Roll 5K

St. Louis | 30 mi from O'Fallon

5 km

Nov

2

Sunday

The Whiskey Run - St. Louis / St. Charles

Saint Charles | 11 mi from O'Fallon

Trail Run 5 km 10 km Half Marathon