The event kicks off at 9:30 a.m. PDT, and users can head to the event page on Google+ to say they'll be attending. The link can also be used to watch the live stream.
Vic Gundotra, the head of the Google+ team, has been busy teasing the event all week, posting "Rehearsing for our Google+ update in the morning. I hope you can all join us and watch the live video stream! #momentsthatmatter."
It's unclear what the company has in store, but there are a number of possibilities.
For starters, many think Google may use the event to announce its latest phone, the Nexus 5, and its latest phone software, Android KitKat.
Another possibility could be that Google talks about a mysterious barge in San Francisco Bay that it has been linked to.
Or of course, Google could talk about a new feature for Google+. We aren't sure, but you can tune in to the event and find out.
[Updated 9:33 a.m. PDT Oct. 29: Just before the start of the event Gundotra posted that Google had lost power and was experiencing problems. Gundotra said the company was working furiously to bring everything back online, but said users should expect a delay in the start of the event.]