The Do-Nut Dinette chain was headquartered in Charlotte, NC, and had locations throughout the South.
Though still imcomplete, here is a working list of locations.
11329 Georgia Avenue, Wheaton, Maryland
1307 W. Franklin Ave., Gastonia, NC
141 East Front St., Statesville, NC
429 W. Palmetto, Statesville, NC
111 North Church St., Burlington, NC
511 Summit Ave., Greensboro, NC
702 N. Mangum, Durham, NC
1010 W. Main, Durham, NC
756 Merrimon Ave, Asheville, NC
1722 South Blvd., Charlotte, NC
1623 Central Ave, Charlotte, NC (possible?)
2125 N. Tryon, Charlotte, NC
420 N. Graham, Charlotte, NC
919 Main Street, Anderson, SC
631 Saluda Ave, Columbia, SC
518 Easley Bridge Rd., Greenville, SC (possibly still there?)
Falls Church, VA
20 South St, Front Royal, VA Front Royal, VA
674 N Loudoun St Winchester, VA
W. State Street, Waynesboro, VA
1917 Colley Ave Norfolk, VA
189 Warwick Road, (HV) Newport News, VA
9967 Warwick Blvd, Newport News, VA
628 South Washington, Alexandria, VA
Diner Hunter 
In Burlington there is what appears to be a former Donut Dinette at the intersection of N Church and Vaughn rd .Might have been moved here or address changed,I also think Sadlacks Heros at the intersection of Hillsborough st & Enterprise st in Raleigh was possibly a Donut Dinette building
Looking fir more info on Donut Dinette in Gastonia NC around the 1960s. Mother worked there
I am interested in the Donut Dinette in Waynesboro, Va – especially when it opened and when it closed. I am a graduate of Fishburne Military School and the DD was close to us.