Arthen ap Seisyll
# Arthen ap Seisyll

Arthen son of Seisyll (Welsh: Arthen or Arthgen ap Seisyll; died c. 807) was a king of Ceredigion in Wales of the Early Middle Ages. His father was Seisyll ap Clydog.

The Annals of Wales mentions his death. Phillimore's reconstruction dates the entry to 807.

