Sukhothai Airport

Should be renamed Sawankhalok airport as it is 27kms from New Sukhothai and only 9 km's from Sawankhalok. You will need to book a minibus to get to the airport.

I booked a ticket for the airport minibus for 120 baht from a tour agent (the only agent!) in New Sukhothai. 

Their office is in Th Jarot Withithong (Road).  You will find it between the Sawaddiphong Hotel and the Bridge.