McPhail v Doulton [1970] UKHL 1, also known as Re Baden's Deed Trusts (No 1) is a leading English trusts law case by the House of Lords on the certainty of beneficiaries. It held that so long as any given claimant can clearly be determined to be a beneficiary, or not, a trust is valid. The Lords also remanded the case to the Court of Appeal to be decided on this new legal principle as Re Baden's Deed Trusts (No 2).