Thomas Pakenham may refer to:
Thomas Pakenham (historian) (born 1933), 8th Earl of Longford, Anglo-Irish historian and arborist Thomas Pakenham, 1st Baron Longford (1713–1766), Irish peer and politician Thomas Pakenham (Augher MP) (1649–1703), grandfather of the preceding Thomas Pakenham (Royal Navy officer) (1757–1836), British naval officer and politician Thomas Pakenham, 2nd Earl of Longford (1774–1835), Irish peer Thomas Pakenham, 5th Earl of Longford (1864–1915), Irish peer and soldier Thomas Pakenham (British Army officer) (1826–1913), MP for Antrim