Official due to leave Musee d'Orsay, sadly (8)
I believe the answer is:
mayoress
'official' is the definition.
(I have seen 'Public official' mean 'mayoress' so perhaps 'official' could also mean 'mayoress')
'due to leave musee d'orsay sadly' is the wordplay.
'to leave' is a deletion indicator.
'sadly' indicates an anagram.
'musee'+'dorsay'='museedorsay'
'museedorsay' with 'due' removed is 'mseorsay'.
'mseorsay' anagrammed gives 'MAYORESS'.
(Other definitions for mayoress that I've seen before include "Local dignitary" , "Civic dignitary" , "Public official" , "Female dignitary" , "Head of town council" .)