The incident happened at around 2.45am on 30 December in the Liden Arms car park when a vehicle was involved in a collision with a 36-year-old man, who suffered serious leg injuries.
The victim was taken to the John Radcliffe Hospital where he remains.
A 37-year-old man from Swindon was arrested in the town on Friday evening (4/1/19) on suspicion of causing grievous bodily harm with intent.
He has been released on conditional bail while our enquiries continue.
Anyone with information about the incident should contact Swindon CID on 101, quoting crime reference 54180122820. Alternatively you can call Crimestoppers anonymously on 0800 555111.