William Henry Magan (1820 – c. September 1861) was an Irish Whig, Independent Irish Party and Repeal Association politician. Magan was elected a Repeal Association Member of Parliament (MP) for Westmeath at the 1847 general election and, becoming an Independent Irish Party MP in 1852 and then a Whig again in 1857, held the seat until 1859 when he did not seek re-election.