The company updated its App Status Dashboard at 2:33 p.m. ET to indicate a service disruption for Gmail.
Downrightnow.com, a website that monitors the status of online services, had earlier reported a "likely service disruption."
An outage map on Canadianoutages.com shows most reports in North America, both in the eastern part of the continent and along the Pacific Coast.
Users, mainly in North America, have been complaining on Twitter about Gmail being down, delays in sending and receiving emails and difficulties logging in.
Gmail has more than 900 million users around the world and is used not just by individuals for their personal email but many businesses for their corporate email.