Yes, Chacos are good for flat feet. Chacos pair is a good choice for good arch support due to a deep heel cup in the footbed, which mostly flat feet people demand. At the start, you might have to face some inconvenience as they have a break-in period of around one week. After that, you'll get used to them and feel great comfort and support. Furthermore, if you need extra cushioning underneath your feet, I’d suggest you to Z/cloud Chacos as that feature extra 5mm layer of PU cushioning in the midsole to provide additional support and shock absorption.