The 22-acre riverside attraction came top in a poll by Keep Scotland Beautiful.
The charity runs the Green Flag Award scheme which recognises the best open spaces in the country. Almost 60 parks were awarded Green Flag status this year.
Chief executive Derek Robertson said: “With a record number of Green Flag Award parks being named in Scotland, we can point to genuine improvement in these green spaces, and we congratulate those responsible for park management, and the local communities who are often regularly involved in upkeep and management.
“Locals tell us time and again how valued these areas are for recreation, and in celebrating this Scottish success story, we look for continued improvement next year.”
Dock Park on the east bank of the River Nith is the oldest park in Dumfries and was recently restored with the aid of Lottery cash.
Stirling’s Beechwood Park and Rouken Glen in East Renfrewshire took second and third place in the vote.