Google Groups is a service from Google that provides discussion groups for people sharing common interests. The Groups service also provides a gateway to Usenet newsgroups via a shared user interface.

Google Groups became operational in February 2001, following Google's acquisition of Deja's Usenet archive. (Deja News had been operational since 1995.)

Google Groups offers at least two kinds of discussion group; in both cases users can participate in threaded conversations, either through a web interface or by e-mail. The first kind are forums specific to Google Groups which are inaccessible by NNTP and act more like mailing lists. The second kind are Usenet groups, for which Google Groups acts as gateway and unofficial archive (the Google Groups archive of Usenet newsgroup postings dates back to 1981). Through the Google Groups user interface, users can read and post to Usenet groups.

In addition to accessing Google and Usenet groups, registered users can also set up mailing list archives for e-mail lists that are hosted elsewhere.