Alduin or Aldoin may refer to:
- Alduin or Audoin (died 563/5), King of the Lombards from 546 to 560
- Alduin I of Angoulême (died 916), Count of Angoulême from 886
- Alduin II of Angoulême (died 1032), Count of Angoulême
- Aldoin (bishop of Cefalù) (died 1248)
- Alduin (dragon), the antagonist in The Elder Scrolls V: Skyrim