Maconachie, Maconochie, McOnachie, or MacOnachie is a surname of Scottish origin. Notable persons with the surname include:
Alexander Maconochie, Lord Meadowbank (1777–1861), Scottish judge and politician Alexander Maconochie (penal reformer) (1787–1860) Alexander Maconochie Centre, the gaol in the Australian Capital Territory G. A. Maconachie (1843–1909), army surgeon in British India Grant McConachie (1909 – 1965), Canadian pilot and businessman Ian Maconachie, Irish badminton player Sir Richard Roy Maconachie (1885-1962), British Indian civil servant Maconochie or Machonochie rations, canned food popular in World War II