No. Our library databases also include articles from newspapers and magazines, which are not peer-reviewed. Trade journals are also in our databases and many of these articles do not go through the peer-review process either.
Fortunately, you can limit your search results to peer-reviewed journals. (warning: Sometimes, a few articles might slip through that haven't been peer-reviewed, such as letters to the editor.)
Refine your search in One Search to "Peer-reviewed Journals."
Most of our article databases, such as those from EBSCO and Gale, also provide the option of limiting to peer-reviewed journals.
Still not sure if your article is peer-reviewed? Ask a Librarian!