Thad Allen (born 1949) was a U.S. Coast Guard admiral. Admiral Allen may also refer to:

David Allen (Royal Navy officer) (1933–1994), British Royal Navy rear admiral William Allen (Royal Navy officer) (1792–1864), British Royal Navy rear admiral

See also John Allan (Canadian naval officer) (1928–2014), Canadian Forces vice admiral Sir Thomas Allin, 1st Baronet (1612–1685), British Royal Navy admiral