During the First World War he served as Flag Captain of HMS "Lion" and was present at the Battle of Heligoland Bight in 1914, at the Battle of Dogger Bank (1915) in 1915 and at the Battle of Jutland in 1916.
During the First World War he served as Captain of HMS "Lion", flagship of Vice-Admiral Sir David Beatty's Battlecruiser Squadron. Chatfield was present as Beatty's Flag-Captain at the Battle of Heligoland Bight in 1914, at the Battle of Dogger Bank in 1915 and at the Battle of Jutland in 1916.