See all May 2018 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.
Tuesday, May 1
- April Showers Battle of Flowers Series – Primrose in San Antonio, TX
Wednesday, May 2
- April Showers Battle of Flowers Series – Cactus in San Antonio, TX
Saturday, May 5
- 500 Festival Mini Marathon & 5K in Indianapolis, IN
- Clear Creek Half Marathon in Richfield, UT
- Door County Half Marathon & 5K in Fish Creek, WI
- Gateway to the Smokies Half Marathon in Waynesville, NC
- Grayson Highlands Half Marathon & 50K in Mouth of Wilson, VA
- I Ran Flagship Marathons Series – Cambodia in San Antonio, TX
- New Prague Half Marathon, 10K, 5K & Fun Run in New Prague, MN
- Pandora’s Box of Rox Trail Run in Burnet, TX
- Provo City Half Marathon & 5K in Provo City, UT
- Ripon’s Run Half Marathon, Quarter Marathon & 5K in Ripon, CA
- Sugarloaf Ridge 50K & Half Marathon in Santa Rosa, CA
- Trail Nut 10K & Half Marathon in Roanoke, VA
- Tutu Run Half Marathon, 10K & 5K in Nampa, ID
- Whiskey Row Marathon, Half Marathon & 10K in Prescott, AZ
- Wisconsin Marathon, Half Marathon & 5K in Kenosha, WI
Sunday, May 6
- Angry Unicorn Half Marathon & 5K in Wakefield, RI
- Avenue of the Giants Marathon, Half Marathon & 10K in Weott, CA
- Colorado Marathon, Half Marathon, 5K & 10K in Fort Collins, CO
- Des Moines Women’s Half Marathon, 5K & Relay in Des Moines, IA
- Divas Half Marathon & 5K in North Myrtle Beach, SC
- Eau Claire Marathon, Half Marathon, Relay & 5K in Eau Claire, WI
- Flying Pig Marathon & Half Marathon in Cincinnati, OH
- Frederick Running Festival Half Marathon, 5K & Relay in Frederick, MD
- Greenwood Furnace Trail Challenge Half Marathon in Huntingdon, PA
- Kalamazoo Marathon, Borgess Half Marathon, 10K & 5K in Kalamazoo, MI
- Lake Minnetonka Half Marathon in Wayzata, MN
- Lincoln Marathon & Half Marathon in Lincoln, NE
- Michigan Shores Mini & 5K Run in New Buffalo, MI
- Middlebury Maple Run Half Marathon & Relay in Middlebury, VT
- Newburyport River Run Half Marathon & 5K in Newburyport, MA
- OC Marathon, Half Marathon & 5K in Newport Beach, CA
- Pittsburgh Marathon, Half Marathon, 5K & Relay in Pittsburgh, PA
- Providence Rhode Races Marathon, Half Marathon & 5K in Providence, RI
- Run for the Zoo Half Marathon, 10K, 5K & 1-Mile in Albuquerque, NM
- Snohomish Women’s Run Half Marathon & 10K in Everett, WA
- USA Beach Running Championships Half Marathon in Cocoa Beach, FL
Tuesday, May 8
- Mainly Marathons Independence Series – Day 1in Lums Pond SP, DE
Wednesday, May 9
- Mainly Marathons Independence Series – Day 2in Elkton, MD
Thursday, May 10
- Mainly Marathons Independence Series – Day 3in Birdsboro, PA
Friday, May 11
- Mainly Marathons Independence Series – Day 4in Branchville, NJ
Saturday, May 12
- Brookings Marathon, Half Marathon, 5K & Relay in Brookings, SD
- Carolina Brewfest Half Marathon in High Point, NC
- Cleveland Half Marathon in Cleveland, TN
- Dino Half Marathon in Vernal, UT
- Ears2U Half Marathon in Meridian, ID
- Fast Half Marathon in South Hamilton, MA
- Flight of Fire Half Marathon, 10K & 5K in Las Vegas, NV
- Get It Dunn Half Marathon & 5K in Menomonie, WI
- Greenbrier Half Marathon in White Sulphur Springs, WV
- Happy Half at Holiday Valley in Ellicottville, NY
- Hippie Chick Half Marathon, 15K & Quarter Marathon in Hillsboro, OR
- Ice Age Trail Run Half Marathon, 50-Mile & 50K in La Grange, WI
- Journeys Marathon, Half Marathon, 10K & 5K in Eagle River, WI
- Kings & Queens Half Marathon in Pewaukee, WI
- Maine Coast Half Marathon in Biddeford, ME
- Mainly Marathons Independence Series – Day 5 in Port Jervis, NY
- Mill Stone Half Marathon Trail Race in Fort Mill, SC
- Muir Woods Marathon, Half Marathon & 7-Mile in Stinson Beach, CA
- Night of Fire Trail Half Marathon, 10K & 5K in Las Vegas, NV
- Rabbit Valley Half Marathon in Fruita, CO
- Races For All Paces Half Marathon, 10K & 5K in Charleston, IL
- Rhinebeck Hudson Valley Marathon & Half Marathon in Rhinebeck, NY
- Running with the Cows Half Marathon in Bucyrus, KS
- Samuel Adams Starved Rock Marathon & Half Marathon in Ottawa, IL
- Santa Barbara Wine Country Half Marathon in Santa Ynez, CA
- Texas Switchback Marathon, Half Marathon & 10K in Johnson City, TX
- Vigor Big Cottonwood Canyon Half Marathon, 10K & 5K in Cottonwood Heights, UT
- Wildcat Half Marathon, 10K & 5K in El Sobrante, CA
- Yosemite Half Marathon in Bass Lake, CA
Sunday, May 13
- Brooklyn Mother’s Day Half Marathon in Brooklyn, NY
- Girls on the Go Half Marathon, 10K & 5K in San Diego, CA
- I Ran Flagship Marathons Series – Cameroon in San Antonio, TX
- Mainly Marathons Independence Series – Day 6 in Matamoras, PA
- Smith Rock Road Half Marathon & 10K in Terrebonne, OR
- Western Mass Mother’s Day Half Marathon in Whatley, MA
Monday, May 14
- Pine Tree Marathon & Half Marathon in Portland, ME
Tuesday, May 15
- Granite State Marathon & Half Marathon in Nashua, NH
Wednesday, May 16
- Maple Leaf Marathon & Half Marathon in Brattleboro, VT
Thursday, May 17
- Old Colony Marathon & Half Marathon in Westfield, MA
Friday, May 18
- Nutmeg State Marathon & Half Marathon in Hartford, CT
Saturday, May 19
- Big Lake Half Marathon in Alton, NH
- Dandelion Run Half Marathon in Derby, VT
- Fargo Marathon, Half Marathon & 10K in Fargo, ND
- Geist Half Marathon, 10K & 5K in Fishers, IN
- Governor’s Cup Road Race Half Marathon in Columbia, SC
- Horse Capital Marathon & Half Marathon in Lexington, KY
- Huff to Bluff Marathon & Half Marathon in Blanding, UT
- I Ran Flagship Marathons Series – Central African Republic in San Antonio, TX
- Jemez Mountain Trail Runs 15-Mile, 50K & 50M in Los Alamos, NM
- Joplin Memorial Marathon, Half Marathon, Relay & 5K in Joplin, MO
- Madeline Island Marathon & Half Marathon in La Pointe, WI
- Martha’s Vineyard Marathon & Half Marathon in Oak Bluffs, MA
- Mine Shaft Half in Golden, CO
- New Castle Mini Marathon in New Castle, IN
- Red Island Marathon & Half Marathon in Warwick, RI
- Red River High Mountain Half Marathon & 5K in Red River, NM
- Run for 57th AHC Half Marathon, 5K & Fun Walk in Possum Kingdom Lake, TX
- Run Sunset Beach Half Marathon & 5K in Sunset Beach, NC
- St. Michaels Running Festival Half Marathon & 5K in St. Michaels, MD
- To Do My Best Half Marathon, 10K & 5K in Piqua, OH
- Uff Da Run Half Marathon & 5K in Woodville, WI
- Woodside King’s Mountain Half Marathon & 5-Mile in Woodside, CA
- Zions Bank Ogden Marathon, Half Marathon & 5K in Ogden, UT
Sunday, May 20
- Avenue of the Vines Half Marathon & 5K in Lodi, CA
- Capital City Marathon, Half Marathon & 5-Mile in Olympia, WA
- Cellcom Green Bay Marathon, Half Marathon & Relay in Green Bay, WI
- Chicago Spring Half Marathon & 10K in Chicago, IL
- Colfax Marathon, Half Marathon, Relay & Urban 10-Miler in Denver, CO
- Marine Corps Historic Half Marathon in Fredericksburg, VA
- Papillion Half Marathon, 10K & 5K in Papillion, NE
- Rite Aid Cleveland Marathon, Half Marathon, & 10K in Cleveland, OH
- Run and Ride Valleyfair Half Marathon, Quarter Marathon & 5K in Shakopee, MN
- Run on the River Half Marathon, 10K & 5K in Astoria, OR
- Smoky Mountain Scottish Festival & Games Half Marathon & 5K in Maryville, TN
- Surfer’s Path Marathon & Capitola Half Marathon in Santa Cruz, CA
- Wallis Sands Half Marathon in Rye, NH
Tuesday, May 22
- I Ran Marathons Memorial Heroes Series – Crazy Horse in San Antonio, TX
Wednesday, May 23
- I Ran Marathons Memorial Heroes Series – MLK in San Antonio, TX
Thursday, May 24
- I Ran Marathons Memorial Heroes Series – JFK in San Antonio, TX
Friday, May 25
- I Ran Marathons Memorial Heroes Series – Air Force in San Antonio, TX
Saturday, May 26
- Bayshore Marathon, Half Marathon & 10K in Traverse City, MI
- Downhill @ Dawn Half Marathon in Ridgecrest, NC
- Eastern Oregon Half Marathon in Spray, OR
- Great American River Run Half Marathon & 5K in Memphis, TN
- Happy Girls Run Half Marathon, 10K & 5K in Bend, OR
- I Ran Marathons Memorial Heroes Series – Navy in San Antonio, TX
- Medina Half Marathon & 5K in Medina, OH
- Memorial Day Half Marathon, 10K & 5K in Gervais, OR
- Noblesville Mini Marathon, 10K & 5K in Noblesville, IN
- Oregon Spring Half Marathon in St. Paul, OR
- The Oz Run in Chippewa Falls, WI
- Road to Carthage Marathon, Half Marathon, Relay & 5K in Nauvoo, IL
- Stafford’s Top of Michigan Community Marathon, Half Marathon & 10K in Harbor Springs, MI
- Trail Factor Half Marathon in Portland, OR
- Viking Dash Trail Run Half Marathon, 15K & 5K – Louisville in Fairdale, KY
Sunday, May 27
- Boston’s Run to Remember Half Marathon & 5 Mile in Boston, MA
- Buffalo Marathon, Half Marathon & Relay in Buffalo, NY
- Herald of Victory Marathon & Half Marathon in Binghamton, NY
- Hibiscus Half Marathon, 15K & 5-Miler in Honolulu, HI
- I Ran Flagship Marathons Series – Chad in San Antonio, TX
- I Ran Marathons Memorial Heroes Series – Army in San Antonio, TX
- Med City Marathon, Half Marathon, Relay & 20-Mile in Rochester, MN
- Mountains 2 Beach Marathon & Half Marathon in Ventura, CA
- Run Madtown Half Marathon, 10K & 5K in Madison, WI
- Wyoming Marathon Races Medicine Bow Half Marathon in Laramie, WY
Monday, May 28
- City of Laguna Hills Memorial Day Half Marathon, 5K & 10K in Laguna Hills, CA
- I Ran Marathons Memorial Heroes Series – Marine in San Antonio, TX
- Sweet Southern Discomfort Marathon, Half Marathon, 10K & 5K in Guntersville, AL
