Nest, founded in 2010, is the team behind the Nest smart thermostat and also a smart smoke alarm, Nest Protect.
Reuters reported the company had raised a total of $230 million in funding since its inception, and Google Ventures led Nest's Series B round in August 2011 as well as its Series C in 2012.
Nest’s founder Tony Fadell previously helped create Apple's iPod and iPhone and will keep running the product under its own brand, according to Google.
"This decision wasn't made on a whim," Fadell wrote in a blog post.
"I know that joining Google will be an easy transition because we're partnering with a company that gets what we do and who we are at Nest - and wants us to stay that way."
"Nest's product line obviously caught the attention of Google and I'm betting that there's a lot of cool stuff we could do together, but nothing to share today," Nest co-founder Matt Rogers said in another blog post on the Nest blog.
The purchase of Nest marks the next step in Google's foothold into your home - an effort that includes Chromecast, Google Glass and other Android devices.
Nest says it has more than 300 employees in three countries as well as a network of more than 25,000 certified professionals who help install Nest in the U.S. and Canada.
The deal is expected to close in the next few months and terms weren't disclosed.