NOTE: Many races have been cancelled, postponed, or switched to virtual-only due to the ongoing COVID-19 pandemic. We’re doing our best to update information as soon as possible, but check the race’s website for the latest details.
See all May 2021 half marathons across the USA below, or click Race Calendars above to see each state’s calendar. For each race, you’ll find course maps, elevation profiles, reviews and info on how to register.
Saturday, May 1
Sunday, May 2
Saturday, May 8
Sunday, May 9
| Sun May 9 | Brooklyn Mother's Day Half Marathon 10K & 5K | Brooklyn NY |
| Sun May 9 | Gasparilla Distance Classic Half Marathon & 8K | Tampa FL |
| Sun May 9 | Gresham Lilac Run Half Marathon & 10K | Gresham OR |
| Sun May 9 | Mother's Day Half Marathon & 5K | Kirkland WA |
| Sun May 9 | Prairie Series Marathon Half Marathon 10K & 5K – Day 1 | Breckenridge MN |
| Sun May 9 | Run This Mother Half Marathon & 5K | San Antonio TX |
| Sun May 9 | Wildflower Trail Marathon Half Marathon & 7-Mile | Bastrop TX |
Monday, May 10 – Friday, May 14
| Mon May 10 | Prairie Series Marathon Half Marathon 10K & 5K – Day 2 | Breckenridge MN |
| Tue May 11 | Prairie Series Marathon Half Marathon 10K & 5K – Day 3 | Baltic SD |
| Wed May 12 | Prairie Series Marathon Half Marathon 10K & 5K – Day 4 | Sioux City IA |
| Thu May 13 | Prairie Series Marathon Half Marathon 10K & 5K – Day 5 | South Sioux City NE |
Saturday, May 15
| Sat May 15 | Brookings Marathon Half Marathon & Relay | Brookings SD |
| Sat May 15 | Clear Creek Half Marathon | Sevier UT |
| Sat May 15 | Cleveland Half Marathon | Cleveland TN |
| Sat May 15 | Dayton Spring Half Marathon & 5K | Dayton OH |
| Sat May 15 | Flower Moon Trail Marathon Half Marathon 50-Mile & 5K | Pawhuska OK |
| Sat May 15 | Harpers Ferry Half Marathon | Harpers Ferry WV |
| Sat May 15 | Hidden Hills Ultra Marathon Half Marathon 50-Mile 10K & 5K | Strawn TX |
| Sat May 15 | Independence Bowl Kickoff K's Half Marathon & 5K | Shreveport LA |
| Sat May 15 | La Jolla Half Marathon & 5K | La Jolla CA |
| Sat May 15 | Mountains to Main Street Half Marathon | Greenville SC |
| Sat May 15 | Prairie Series Marathon Half Marathon 10K & 5K – Day 7 | St. Joseph MO |
| Sat May 15 | Race4Warriors Marathon Half Marathon 10K & 5K | Lewes DE |
| Sat May 15 | San Juan Island Half Marathon | Friday Harbor WA |
| Sat May 15 | Vallecito Lake Heavy Half | Bayfield CO |
Sunday, May 16
| Sun May 16 | Chicagoland Spring Marathon & Half Marathon | Schaumburg IL |
| Sun May 16 | Crazy Clam Half Marathon 5-Mile & 5K | Smithfield RI |
| Sun May 16 | Earth Rock Run Half Marathon | Amesbury MA |
| Sun May 16 | Happy Valley Half Marathon | Northampton MA |
| Sun May 16 | Lake Trail Half Marathon 10K & 5K | Fairfax Station VA |
| Sun May 16 | Michigan Shores Mini Half Marathon & 5K | New Buffalo MI |
| Sun May 16 | Rite-Aid Cleveland Marathon & Half Marathon | Cleveland OH |
| Sun May 16 | Tobacco Road Marathon & Half Marathon | Cary NC |
| Sun May 16 | Vermont Sun Half Marathon 10K & 5K | Lake Dunmore VT |
| Sun May 16 | Windermere Marathon & Half Marathon | Spokane WA |
Monday, May 17 – Friday, May 21
| Mon May 17 | Pine Tree Marathon & Half Marathon | Portland ME |
| Tue May 18 | Granite State Marathon & Half Marathon | Nashua NH |
| Wed May 19 | Maple Leaf Marathon & Half Marathon | Springfield VT |
| Thu May 20 | Old Colony Marathon & Half Marathon | Westfield MA |
| Fri May 21 | Nutmeg State Marathon & Half Marathon | Hartford CT |
Saturday, May 22
| Sat May 22 | Bill Snyder Highway Half Marathon & 5K | Manhattan KS |
| Sat May 22 | Dances with Dirt Gnaw Bone Half Marathon | Nashville IN |
| Sat May 22 | Dandelion Run Half Marathon 10K & 4-Mile | Derby VT |
| Sat May 22 | DeWitt Take a Breath for PH and Get Moving for MS Half Marathon | DeWitt MI |
| Sat May 22 | Fiesta de Mayo Half Marathon 10K & 5K | Irving TX |
| Sat May 22 | Fountainhead Half Marathon & 10K | Fairfax Station VA |
| Sat May 22 | Hamden Hills Half Marathon & 5K | Hamden CT |
| Sat May 22 | Madeline Island Marathon & Half Marathon | La Pointe WI |
| Sat May 22 | Martha's Vineyard Marathon Half Marathon & Relay | Oak Bluffs MA |
| Sat May 22 | Red Island Marathon & Half Marathon | Warwick RI |
| Sat May 22 | Soaring Eagle Half Marathon 10K & 5K | Sammamish WA |
| Sat May 22 | Thelma and Louise Marathon Half Marathon 10K & Relay | Moab UT |
| Sat May 22 | Whitefish Marathon Half Marathon & 5K | Whitefish MT |
| Sat May 22 | Zachariah's Acres Spring Run Walk & Roll Half Marathon & 5K | Oconomowoc WI |
Sunday, May 23
| Sun May 23 | 406 Queen Bee Half Marathon 10K & 5K | Billings MT |
| Sun May 23 | Barr Lake Half Marathon & 15K | Brighton CO |
| Sun May 23 | Chicago Spring Half Marathon & 10K | Chicago IL |
| Sun May 23 | Fountainhead Half Marathon & 10K | Fairfax Station VA |
| Sun May 23 | Great Sacandaga Half Marathon | Northville NY |
| Sun May 23 | Omaha Women's Half Marathon & 5K | Omaha NE |
| Sun May 23 | Reflection Run Half Marathon 10K & 5K | Washougal WA |
| Sun May 23 | SHE Power Half Marathon & 5K | Indianapolis IN |
| Sun May 23 | Spring Georgetown Half Marathon & 5K | Washington DC |
| Sun May 23 | Willamette Valley Marathon Half Marathon 10K & Relay | Salem OR |
Saturday, May 29
| Sat May 29 | Armed Forces Half Marathon & 12K | Concord CA |
| Sat May 29 | Dash Around Kampeska Half Marathon & Relay | Watertown SD |
| Sat May 29 | Great American River Run Half Marathon & 5K | Memphis TN |
| Sat May 29 | Growing Green Challenge Half Marathon & Half-of-a-Half | Rush City MN |
| Sat May 29 | Happy Girls Run Half Marathon 10K & 5K | Bend OR |
| Sat May 29 | Multiple Sclerosis Marathon & Half Marathon | Dallas TX |
| Sat May 29 | Prince of Wales Island Marathon Half Marathon & Relay | Craig AK |
| Sat May 29 | Salute the Troops Half Marathon & 5K | Fond du Lac WI |
| Sat May 29 | Spring Memorial Half Marathon 10K & 5K | Springfield VA |
| Sat May 29 | Stumptown Trail Half Marathon | Portland OR |
| Sat May 29 | Trent-Waldron Glacier Half Marathon & 10K | Anchorage AK |
| Sat May 29 | Valkyrie Trail Marathon Half Marathon 50K & 4-Mile | Colorado Springs CO |
| Sat May 29 | Wonderland Mountain Challenge Half Marathon & 10K | Oak Hill WV |
Sunday, May 30
| Sun May 30 | Badass Texas Half Marathon 10K & 5K | Waco TX |
| Sun May 30 | Bobcat Marathon Half Marathon 50K 10K & 5K | Proctorville OH |
| Sun May 30 | Buffalo Marathon Half Marathon & Relay | Buffalo NY |
| Sun May 30 | Coeur d'Alene Marathon Half Marathon 10K & 5K | Coeur d'Alene ID |
| Sun May 30 | Laurel Memorial Half Marathon 10K & 5K | Lorton VA |
| Sun May 30 | Memorial Day Run Half Marathon 10K & 5K | Lyons WI |
| Sun May 30 | Minocqua Northwoods Escape Marathon Half Marathon & 5K | Minocqua WI |
| Sun May 30 | Mountains 2 Beach Marathon & Half Marathon | Ventura CA |
| Sun May 30 | North Mitten Half Marathon 10K & 5K | Thompsonville MI |
| Sun May 30 | Wayne's World Marathon & Half Marathon | Dallas TX |
Monday, May 31
| Mon May 31 | Fallen Soldiers Memorial Half Marathon 10K & 5K | Great Falls MD |
| Mon May 31 | Georgia Peach Jam Half Marathon & 5K | Cumming GA |
| Mon May 31 | Memorial Day Marathon & Half Marathon | Dallas TX |
| Mon May 31 | Salamander State Marathon Half Marathon 50K 10K & 5K | Huntington WV |
