Re Diplock or Chichester Diocesan Fund and Board of Finance Inc v Simpson [1944] AC 341 is an English trusts law and unjust enrichment case, concerning tracing and an action for money had and received.

But the trust was held to be invalid in a decision of the House of Lords, called Chichester Diocesan Fund and Board of Finance Incorporated v Simpson.

[3] The Court of Chancery, it was said, acted upon the conscience, and, unless the defendant had behaved in an unconscientious manner, would make no decree against him.

The appellant or those through whom he claimed, having received a legacy in good faith and having spent it without knowledge of any flaw in their title, ought not in conscience to be ordered to refund.

Upon the propriety of a legatee refusing to repay to the true owner the money that he has wrongly received I do not think it necessary to express any judgment.

The broad fact remains that the Court of Chancery, in order to mitigate the rigour of the common law or to supply its deficiencies, established the rule of equity which I have described and this rule did not excuse the wrongly paid legatee from repayment because he had spent what he had been wrongly paid.