Microsoft Graph provides access to useful people data.
You can use the person resource and the People API to aggregate information about a person from across mail, contacts, and social networks. The results are ordered by their relevance based on multiple communication and collaboration patterns and business relationships. The API lets you browse, sort, select, filter, or search for persons based on your criteria.
For scenarios and examples, see Get information about relevant people.
To use the API, see the following: