Bicester Village Station has been rebuilt from the former Bicester Town station, to form part of Chiltern Railway's new Â£130m Oxford to London Marylebone rail link.
Rob Brighouse, managing director at Chiltern Railways, said: "The team has been working exceptionally hard to reach this significant milestone."
The station is due to open in October.
Two trains an hour will run to London from Bicester Village station, with a fastest journey time of 46 minutes at peak times, Chiltern Railways said.
The new station has two new platforms, a rebuilt car park, and a new approach road.
Andy Milne, senior programme engineer at Network Rail, called it a "real step forward in reconnecting the railway from Oxford and Bicester towards Bletchley, Milton Keynes and Bedford, bringing huge economic benefits to the whole area".
Mr Brighouse said the rail link would be the first "between a major British city [Oxford] and London for over 100 years".
The renaming of the station was met with criticism by some residents, who felt it took focus away from the town in favour of Bicester Village, a popular retail outlet to out-of town-shoppers.
The town's other station is Bicester North on the Chiltern Main Line.
The structure of a new railway station in an Oxfordshire market town has been completed.