Blackthorn is a village and civil parish in the Cherwell District of Oxfordshire about 3 miles (5 km) southeast of Bicester.

Newer housing on the east side of the neighbouring village of Ambrosden is in the parish of Blackthorn.

Charles Bagshawe, who was vicar of Ambosden 1866–1884, ran a mission room in Blackthorn.

[2] The mission room has since closed and Blackthorn has reverted to being served by the parish church of St. Mary the Virgin, 1.5 miles (2.4 km) away in Ambrosden, part of the Benefice of the Ray Valley.

[2] Stone Pits Farm in the parish is named after a quarry that supplied limestone for building.

In the 1740s stone from here was used to build Ambrosden House for Sir Edward Turner, 2nd Baronet.

[6] West Mill had a rendered exterior and a fantail; by the early 1980s its remains had been reduced to the lower part of the tower.

East Mill was tile-hung,[6] has lost its sails and cap, but the tower survives.

An agricultural depression followed, and the Church Charity responded by reducing its land rents in Blackthorn in 1805 and again between 1822 and 1830.

Overcrowding and an insanitary water supply led to a cholera epidemic in 1823 that killed at least 27 people.

However, the population continued to increase, partly because Blackthorn was an "open village" where it was easy for paupers from outside the parish to move in.

[2] In about 1910 the Great Western Railway built a new main line[2] linking Ashendon Junction and King's Sutton to complete a new high-speed route between its termini at London Paddington and Birmingham Snow Hill.

The line passes within a few hundred yards of Blackthorn and crosses Akeman Street on a steel bridge just north of the village.

[citation needed][10] In 2002 Blackthorn celebrated Queen Elizabeth II's Golden Jubilee with a fête[9] opened by its own Queen of Blackthorn (a young village girl) who paraded around the village and greeted every visitor with a kiss.