With the new feature, searching for a movie title may display show times and professional reviews, but also what a user's friends are saying about it.
The feature will also allow users to browse the profiles of prominent authors and musicians on Google+.
Users will still be able to control who can see the personal content they post on Google+, and Google will protect the private information with the same encryption it uses for its email service.
The feature will not include results from other social networking sites such as Facebook or Twitter, which are mostly inaccessible in search results because of privacy settings and other obstacles.
"Search is simply better with your world in it, and we’re just getting started," Google wrote.
The move is likely an attempt to encourage more people to join Google+, which still lags far behind Facebook.
But the changes come with the Web giant's business practices already under scrutiny from the Federal Trade Commission (FTC).
Lawmakers including Sens. Herb Kohl (D-Wis.) and Mike Lee (R-Utah) have questioned whether Google is using its dominant position in online searches to give it an unfair advantage in other markets by ranking its own services — such as Google Maps, Google Travel or YouTube — higher in search results.
Google settled charges with the FTC last year that it misled consumers by automatically opting them in to its now defunct social network, Google Buzz.
The settlement bars Google from misrepresenting its privacy policies and requires the company to submit to outside privacy audits.
Facebook also settled charges with the FTC in November that it failed to follow its own privacy policies. The FTC complaint accused Facebook of sharing its users’ personal information with advertisers and changing its privacy policies without obtaining its users' consent.