5K run and 1-mile fun walk to mark the opening of Winter Wonderfest. At Hudson Fields, 29763 Eagle Crest Rd., Milton. 5 p.m. for the run, 6 p.m. for the walk. Info: wonderfestdeorg.
Run for the Arts, to benefit the Mispillion Art League, Milford. 10 a.m. at Arena’s restaurant, 200 NE Front St. After-race party at Park Place restaurant, 5 N. Washington St. Info: seashorestriders.com.
5K run and walk to benefit the Delaware chapter of the Prader-Willi Syndrome Association. In and around Milton, starting at the Irish Eyes Pub & Restaurant at 106 Union St. 9 a.m. Info: seashorestriders.com. For information about the syndrome: pwsausa.org.
Gabby Gobble 5K run. Starting at 9:30 a.m. at Irish Eyes Pub, Lewes. Kiddie fun run at 9 a.m. Benefits the Get Well Gabby Foundation, which supports research on childhood brain cancer. Info: races2run.com. For information about the foundation: getwellgabby.org.
Huffin’ for Pumpkin Pie 5K Run and 1-mile walk. 9 a.m. at Grove Park, Rehoboth Beach. Info: seashorestriders.com.
Sea Colony Turkey Trot 5K. At the Freeman Fitness Center, Bethany Beach.9 a.m. Benefits Special Olympics Delaware. Info: seashorestriders.com.
Rehoboth Seashore Marathon and Half-Marathon. Starting at 7 a.m. at the Rehoboth Beach bandstand. After-party at The Cultured Pearl and the Shops at the Pearl, 301 Rehoboth Ave. Info: rbmarathon.com.
Santa Cause 5K and 1-mile fun run, to benefit Children & Families First, dedicated to helping at-risk children in Sussex County. Noon at the Starboard restaurant, Dewey Beach. Holiday costumes encouraged. Also games, crafts and activities for children. Info: cffde.org or 604-6277.
Run with Santa 5K. Starting at 10 a.m. at the fishing pier at Cape Henlopen State Park near Lewes. Runners are welcome to wear Santa suits. Canned food that is collected that day will be donated to the Sussex County Needy Family Fund. Info: seashorestriders.com.
Race into the New Year 5K. Starting at noon at the Rehoboth Beach bandstand. Includes a 1⁄4-mile fun run for children younger than age 12. Info: seashorestriders.com.
Hair of the Dog 5K and 10K, sponsored by the Quiet Resorts Charitable Foundation, the charitable arm of the Bethany-Fenwick Area Chamber of Commerce. 10K starts at 8:30 a.m., 5K at 10 a.m. in downtown Bethany Beach. Post-race party at Mango’s, 97 Garfield Parkway. Info: qrcf.org or 537-7723.