A Christmas tree is a common decoration for the holiday season. You can purchase one from a local store that sells Christmas decorations, such as a department store or a home goods store. Some grocery stores and even gas stations may also sell Christmas trees during the holiday season. Additionally, there are often Christmas tree farms where you can cut down your own tree or choose from pre-cut trees. You can also find online retailers that sell Christmas trees, and some charities even sell trees as a fundraiser.