There is no official anthem for Wessex. In an ideal world, Jerusalem, inspired by the legend of the boy Jesus visiting Glastonbury with Joseph of Arimathea and set to music by Hubert Parry in Gloucestershire, would be the choice. But as the de facto national anthem of England, it cannot be said to be uniquely ours.
Wessex Society did commission an anthem, The Very Nëame of Wessex, with music by Hayley Savage and lyrics by Devina Symes, but sadly, it never really caught on. Our own Jim Gunter has written a verse of an anthem, to be sung to the tune of The Red Flag/O Tannenbaum:
Again, with it being set to such a familiar tune, one can question the extent to which it is truly ours. But it is often sung at the beginning of Wessex Society meetings nonetheless. Perhaps one day, a Wessex composer might pen a song that is universally recognised within the region as the anthem of Wessex.