Queen follows favourite saint (5)
I believe the answer is:
peter
'saint' is the definition.
(I know that Peter is a saint)
'queen follows favourite' is the wordplay.
'queen' becomes 'ER' (abbreviation for Elizabeth Regina).
'follows' is a charade indicator (letters next to each other).
'favourite' becomes 'pet' (synonyms).
'er' after 'pet' is 'PETER'.
(Other definitions for peter that I've seen before include "Leading apostle" , "prison cell" , "and 14 dn Latest actor to play Doctor Who" , "- Grimes (Britten)" , "Saint at the Pearly Gates?" .)