A trustor, also called a "grantor," "settler," or "creator," is the person who creates a trust. The trustor grants real property, personal property, money, and gifts to the beneficiaries in the trust. They may are sometimes referred to as a "donor," as they are granting something to another party. The names vary according to jurisdiction, but the definition and role is basically the same.

A trust is a legal document in which one person provides assets to the beneficiaries, and directs a trustee to manage and administer the assets until the trust property is transferred and the trust is no longer in effect. When the trustor and trustee are the same person, the trust is called a grantor trust. A beneficiary to a trust receives the property or income according the terms of the trust, which can be spread out over years or given in a lump sum when certain conditions are met. In some cases, the grantor can also be a beneficiary to the trust.

The trustor usually sets the terms of the trust and signs a trust agreement. The agreement details the instructions to the trustee for how to manage the trust. Any trust agreement that involves land is required to be in writing in order to be enforceable, but other trust agreements can be oral or even implied. The agreement often states how the principal and income of the trust are to be invested and disbursed to the beneficiaries. The trustee has to adhere to the trust agreement when administering his duties, or he can be sued by the beneficiaries for breach of duty under trust law.

A trust can be created during the trustor's lifetime, which is called a living trust. The primary benefit to establishing a living trust is to avoid the need to go to probate. Another option is to create a trust as part of a will, which is a testamentary trust. The trust property can and often does go to probate, because the assets must pass through the estate. The trustor can revoke, change, or cancel a living trust or testamentary trust, unless it is an irrevocable living trust.

A trustor often creates a trust to replace a will, but a trust can be a part of a will as well. A trust attorney can provide advise on the best type of trust to create, based on individual circumstances, the trust law that will govern the trust, and the tax system that affects it. Giving gifts up to a certain amount may be a better alternative, depending on the beneficiaries and tax consequences.