A legal document (which may be a deed or other instrument) that creates a trust. The trust document appoints the trustees and states the terms of the trust, including who the beneficiaries are and the trust property that will be subject to the trust.

In England and Wales the trust document usually takes the form of a trust deed. If the trust deed is created by the trustees (which may happen if the trustee is also the settlor, or if the settlor does not wish his name to appear on the trust deed), it is called a declaration of trust.