According to WIKI:-   Carl Sigman wrote the words and music for the theme song which was sung by Dick James and is still fondly remembered:

Robin Hood, Robin Hood, riding through the glen
Robin Hood, Robin Hood, with his band of men
Feared by the bad, loved by the good;
Robin Hood, Robin Hood, Robin Hood!

He called the greatest archers to a tavern on the green,
They vowed to help the people of the king,
They handled all the trouble on the English country scene,
And still found plenty of time to sing...
(Chorus repeat)


The song was released as a single by Gary Miller and reached number 10 on the UK charts.