Mastercard Cirrus is a worldwide interbank network that provides cash to Mastercard cardholders. As a subsidiary of Mastercard Inc., it connects all Mastercard credit, debit and prepaid cards, as well as ATM cards issued by various banks worldwide bearing the Mastercard / Maestro logo.

Founded in 1982, prior to its acquisition by Mastercard in 1987, Cirrus System, LLC was owned by Bank of Montreal, BayBanks Inc., First Interstate Bancorp, Mellon Bank, NBD Bancorp Inc. and Norwest Corp.

By default, Mastercard, Maestro cards are linked to the Cirrus network, but very often all three logotypes will be shown. Canadian, American and Saudi Arabian ATMs use this network alongside their local networks and many banks have adopted Cirrus as their international interbank network alongside either a local network, the rival Plus ATM network owned by Visa, or both. In countries such as India and Bangladesh, the Cirrus network also serves as a local interbank network as well as an international network.