Who sings dreamer nothing but a dreamer?

Yasmin from the song Dreamer by Devlin.

Devlin - Dreamer.

It's on his Blood, Sweat and Beers Album.

Quality stuff.

Another possibility:Supertramp had a hit single called "Dreamer" from their album Crime of the Century, released in 1974. The song peaked at #13 on the UK Singles Chart in February of '75.