Lachlan (or Lauchlan) Mackinnon (or MacKinnon or McKinnon) may refer to:

• Sir Lachlan Mackinnon (clan chief) (died c.1634), chief of the Scottish Highland clan Mackinnon
• Lauchlan Bellingham Mackinnon (1814–1877), Member of Parliament for Rye, Sussex, England
• Lauchlan Mackinnon (1817–1888), Australian pastoralist, politician and newspaper proprietor
• Lachlan Donald Ian Mackinnon (1882–1948), Royal Navy officer
• Lachlan Mackinnon (born 1956), Scottish poet, critic and literary journalist