Yes! A team owner in Microsoft Teams can add and manage guests in their teams via the web or desktop. Anyone with a business or consumer email accounts, such as Outlook, Gmail, or others, can participate as a guest in Teams with full access to team chats, meetings, and files. Only people who are outside of your organization, such as partners or consultants, can be added as guests. People from within your organization can join as regular team members.
This does also require Guest Access to be enabled at the organization level. Best practices are to invite external guests into teams which are meant for them. There are security implications with inviting outside users into your internal company teams which companies should consider before enabling this.