Parts of some of the famous beaches on Thassos are reserved for nudists. The most famous one which nudists can also enjoy is Paradise beach in its eastern part (left while looking at the sea). In addition to that, there are many beautiful coves beside the beach that are a paradise for nudists.
Trypiti is also one of the popular beaches among nudists. The left part is reserved for them (towards Limenaria), but they can also enjoy the many coves around this beach.
Metalia beach in Limenaria has many hidden coves which are usually used by nudists.
Just before Skala Maries (if you're arriving from the direction of Potos), at the turn for the archaeological site, there are a couple of big coves where you can isolate yourself and enjoy the magic of sea, sun and nudity.
Between Pefkari and Limenaria, and also after San Antonio beach, there are some beautiful, tucked away beaches with turquoise and crystal clear water which are perfect for nudists.