>>
Is Outlook.com included in Office 365?
<<
Hello Paul
For the sake of accuracy, in terms of an Outlook.com account
#1 - Outlook.com is a free email service available to anyone whether or not they have Office 365
#2 - To activate Office 365, you need to create an MS Account. By default, an MS Account has an Outlook.com email account associated with it whether or not the MS Account is associated with Office 365
#3 - When you subscribe to Office 365 - your Outlook.com account is upgraded to "Premium" which among other things removes ads that are shown with a simple free account as well as increasing your email data storage limits as described in the link provided by @Aditya
Now if your question was, by chance, related to the Outlook desktop application then the answer is: Yes it is included in all Office suites <EXCEPT> for Office Home & Student (regardless of actual office version i.e. Office '2010, '2019, '365 etc).