Claflin trust is a trust which cannot be prematurely terminated by the beneficiary if it contravenes the wishes settlor. If a deceased settlor has evinced a clear intent in the trust agreement that the trust operate perpetually, it is difficult, if not impossible, to challenge that operation. Termination of trust by beneficiaries in advance of the time for termination under its terms is prohibited if such termination would defeat the material purpose of the settlor.

The trust derives is name from the case Claflin v. Claflin, 20 N.E. 454 (Mass. 1889), wherein it was held that a testator has a right to dispose of his own property with such restrictions and limitations, not repugnant to law, as he sees fit, and his intentions ought to be carried out unless they contravene some positive rule of law or are against public policy. In the U.S. Claflin doctrine prohibits any modification or termination of the trust if such change contravenes the clear intent of the settlor.

Claflin trusts are also known as indestructible trust