Christopher Ewart-Biggs (died July 21, 1976) was the British Ambassador to the Republic of Ireland. He was assassinated by the Provisional IRA in Sandymount, County Dublin. His widow, (the late) Jane Ewart-Biggs, campaigned to improve Anglo-Irish relations.

Ewart-Biggs was 54 when he was killed by a landmine presumably planted by the IRA. He had taken previous precautions to avoid such an incident since coming to Dublin only two weeks before the incident (eg: varying his route many times a week), but due to a vulnerable spot on the road connecting his residence to the main road, at one point had only the choice between left or right. He chose right, and approximately 150 yards from the residence, hit a landmine (said to contain hundreds of pounds of explosives). Ewart-Biggs and fellow passenger and civil servant Judith Cooke (aged 26 at the time) were killed. Driver Brian O'Driscoll and third passenger Brian Cubbon (aged 57 and apparently the highest-ranking civil servant in Northern Ireland at the time) were injured.

Ewart-Biggs was a soldier; in the WWII battle of El Alamein in 1942 he lost his right eye, the artificial copy of which he wore a smoked-glass monocle over. Also, as a British consul in Algiers in 1961 (before the French withdrawl), he had been a potential target for assassination by diehard French colonialists.

Thirteen suspected members of the IRA were picked up during raids as the governments hunted the killers down.

The Christopher Ewart-Biggs Memorial Prize was founded in his honour.