William Barclay may refer to: William Barclay (jurist) (1546–1608), Scottish jurist William Barclay (writer) (c. 1570 – c. 1630), Scottish writer William Barclay (painter) (1797–1859), English miniature painter William Barclay (theologian) (1907–1978), theologian and writer of Bible commentaries William Barclay (New York politician) (born 1969), New York State Assemblyman William Barclay (Northern Ireland politician) (1873–1945), Northern Irish Senator William Edward Barclay (1857–1917), football manager of Everton and of Liverpool