A person (or multiple people) who place assets into a trust. When the grantor places the assets in the trust, they become the property of the trust and controlled by the trustee. Frequently, the grantor and the trustee are the same person during the grantor's life. A grantor may also place assets into an irrevocable trust; in that situation, the grantor is generally responsible for any gift taxes due as a result of the transfer of assets to the trust.