Yes, it is possible to block customers on Shopify. Shopify provides a feature called “Customer Blocking” that allows you to prevent specific customers from making purchases or accessing your online store. To block a customer, you can go to the Customers section in your Shopify admin, find the customer you want to block, and click on their name to view their details. From there, you can click on the “More actions” button and select “Block customer” to prevent them from interacting with your store. Keep in mind that blocking a customer will prevent them from making future purchases, but it will not affect any previous orders they have made.