Lampleigh v Brathwait [1615] EWHC KB J 17, (1615) Hobart 105, 80 ER 255 is a case on implied assumpsit and past consideration in English contract law.
Brathwait killed a man called Patrick Mahume unlawfully.
Brathwait said that because the service had been performed in the past, there was no good consideration at the time for the promise, regardless of the fact that Lampleigh was successful in securing a pardon.
Where a past benefit was conferred at the beneficiary's request, and where a reward would reasonably be expected, the promisor would be bound by his promise.
In later centuries, judges have pondered some unsettled issues arising from this case.