William McArthur may refer to:
William Pope McArthur (1814–1850), US naval officer and hydrologist William McArthur (lord mayor of London) (1809–1887), Irish businessman, MP and Lord Mayor of London William Alexander McArthur (1857–1923), British politician William S. McArthur (born 1951), US astronaut Sir William MacArthur (British Army officer), Director General Army Medical Services Bill McArthur (American football), American football player and coach See also William Macarthur (1800–1882), Australian horticulturist and politician