Vic Gundotra had been at Google since 2007, and was the company’s vice-president for social media.While boasting a large number of users, Google+ is still considered to be very much in the shadow of other networks – particularly Facebook and Twitter.
Chief executive Larry Page thanked Mr Gundotra for “all his hard work and passion” at the company.
Mr Gundotra, who previously worked at Microsoft, will be replaced by David Besbris, who is currently vice-president of engineering on the network.
Google+ was launched in June 2011, and the latest figures released by the firm suggest it has 540 million users.