Ollie's partner, famous comedian in carriage (8)
I believe the answer is:
stanhope
'carriage' is the definition.
(I've seen this before)
'ollie's partner famous comedian' is the wordplay.
'ollie's partner' becomes 'stan' (I've seen this before).
'famous comedian' becomes 'hope' (I can't explain this - if you can you should give a lot more credence to this answer).
'stan'+'hope'='STANHOPE'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for stanhope that I've seen before include "Phaetons can be turned into a light open one-seater carriage" , "It may have only two wheels" , "Light horse-drawn carriage; Nineteen across (anag.)" , "old-fashioned conveyance" , "carriage that has seat only for one" .)