A custodial account is a financial account (such as a bank account, a trust fund or a brokerage account) set up for the benefit of a beneficiary, and administered by a responsible person, known as a legal guardian or custodian, who has a fiduciary obligation to the beneficiary.

Custodial accounts come in a number of forms, one being an account set up for a minor, since the minor is under the legal age of majority. The custodian is often the minor's parent. In the U.S., this type of account is often structured as a Coverdell ESA, allowing for tax-advantaged treatment of educational expenses. Another form is a trust account owned by an individual or institution, managed by a named party for purposes of rapid distribution of funds in that account. This is commonly used for petty cash, or for transactions that have very limited and clearly defined payees and transaction types. For example, law firm accounting includes trust accounts for disbursing funds entrusted to the law firm by each client for the client's benefit.