Walter Buchanan (1797 – 1877) was a British Whig and Liberal politician.
Buchan was elected Whig MP for Glasgow at a by-election in 1857—caused by the resignation of John MacGregor—and, becoming a Liberal in 1859, held the seat until 1865 when he did not seek re-election.
He married Christina Laura Smith, daughter of James Smith of Jordanhill, in 1851; she died in 1853.