Richard Childress Racing said Dillon tested positive Saturday morning. He experienced mild symptoms and sought a test on his own. He is now self-quarantining from the team. His wife and newborn son remain healthy and symptom-free, the team added.
Kaz Grala will drive the No. 3 Chevrolet at Daytona on Sunday.
Dillon is the third Cup Series drive to test positive for the coronavirus, joining seven-time champion Jimmie Johnson and part-timer Brendan Gaughan. Johnson missed just one race.
The 30-year-old Dillon already qualified for NASCAR's playoffs by winning at Texas last month.
According to NASCAR's latest COVID-19 protocols, Dillon may return to racing activities after he receives two negative test results taken at least 24 hours apart. He also may return 10 days after his first positive test if he is fever-free for at least 24 hours without the use of medication.
Individuals who have had confirmed exposure to Dillon also are required to remove themselves from competition and self-isolate. Analysis includes contact greater than 10 minutes over the last 10 days, direct skin contact, lack of social distancing and the level of protective equipment used at the time.
They may return to racing activities after they have received one negative test. NASCAR may request a second test for clearance based on the nature of the exposure.