Replacement ink cartridges for Canon inkjet printers are available directly from Canon through the company's website at Canon.com. Many retail and online stores also sell Canon ink cartridges, including Best Buy, Wal-Mart and Cartridge World.
Determining the correct ink cartridge for use with a particular model of Canon printer can be difficult due to the large number of Canon printer models and ink cartridge designs. Canon provides an Ink Finder tool on its website that allows users to look up compatible cartridges for its printers. Users can look for compatible cartridges organized by printer series or by providing a printer's specific model number.