Aynho Junction is a railway junction in Northamptonshire, England, a few miles south of Banbury. The junction is a flying junction, with the down line from Bicester North grade separated from the up and down lines from Oxford. The junction is the point where the Great Western Railway's New North Main Line of 1910 ends. This line is also known as the Bicester cut-off line. Until closure by British Railways in 1963 Aynho Park railway station stood close to the junction on the new line. On the old line Aynho for Deddington railway station was closed the following year.