Neil or Niall Campbell may refer to:
- Sir Neil Campbell, known as Niall mac Cailein (died 1316), hero of the Wars of Scottish Independence
- Neil Campbell (bishop of Argyll) (died 1613), Scots bishop
- Neil Campbell (bishop of the Isles) (c. 1590âÂÂ1645), Scots bishop
- Lord Neill Campbell (c. 1630âÂÂ1692), Scottish nobleman, governor of New Jersey, 1686âÂÂ1687
- Sir Neil Campbell (British Army officer) (1776âÂÂ1827), fought in the Napoleonic Wars
- Neil Campbell (minister) (1678âÂÂ1761), Principal of Glasgow University and Moderator of the General Assembly of the Church of Scotland
- Robert Neil Campbell (1854âÂÂ1928), a Scottish physician, known as Sir Neil Campbell
- Neil Campbell (politician) (1880–1960), Australian politician, Tasmanian Leader of the Opposition from 1945 to 1950
- Neil Campbell (chemist) (1903âÂÂ1996), Scottish chemist and amateur athlete
- Neil Campbell (geologist) (1914âÂÂ1978), Canadian geologist
- Neil Campbell (rower) (1931âÂÂ2006), Canadian rower and coach
- Neil Campbell (scientist) (1946âÂÂ2004), American author of biology textbooks
- Neil Campbell (musician) (born 1966), British experimental musician
- Neil Campbell (footballer) (1977âÂÂ2022), English footballer
- Neil Campbell (producer), comedian, writer, and producer
- Niall Campbell, 10th Duke of Argyll (1872âÂÂ1949), British Lord Lieutenant of Argyllshire
- Niall Campbell (poet), Scottish poet