Facebook Inc. said it is ramping up its global advertising spending as it aims to rebuild trust after a series of privacy missteps and other controversies dented the social-networking giant’s reputation.

The push, which Facebook marketing chief Antonio Lucio said could more than double the company’s advertising spending, will involve working with a revamped roster of creative agencies on campaigns for brands including WhatsApp and Instagram.

Mr. Lucio said the Menlo Park, Calif., firm has been tarred by election interference and misinformation on Facebook as well criticism of its privacy and data management.

“There’s no question we made mistakes and we’re in the process of addressing them one after the other, but we have to tell that story to the world on the trust side as well as on the value side,” Mr. Lucio said.

Facebook has already begun its effort to rebuild trust with consumers, according to Mr. Lucio. The company recently redesigned its mobile app and website to shift from an open public forum to a more private network with encrypted communication in closed groups. Last year it aired an expensive apology ad campaign to repair its image among people upset about the proliferation of fake news on Facebook and Russia’s use of the platform as it tried to influence the U.S. election.

Newsletter Sign-up CMO Today CMO Today delivers the most important news of the day for media and marketing professionals. PREVIEW

Facebook is under intensifying government scrutiny. The Federal Trade Commission began an investigation into the company’s privacy practices more than a year ago, following reports that the personal information of tens of millions of users improperly wound up in the hands of data firm Cambridge Analytica. The FTC has separately secured jurisdiction on any possible antitrust matters related to Facebook.

The overhaul of the consumer-facing strategy could more than double Facebook’s advertising spending in two to three years, Mr. Lucio said. Facebook declined to disclose how much it spends on advertising. Ad-tracking firm Kantar estimated that Facebook shelled out $382 million on ads in the U.S. last year, up from $50 million in 2017.

Brand Stories

To help get its message to the masses, the tech giant is revamping the roster of ad agencies it will use to craft campaigns promoting each brand—including Facebook’s own corporate brand—in the U.S. and around the world.

A multiyear consumer effort tasking agencies to create brand stories across a number of markets around the world is a shift from hiring shops for specific projects, many of them aimed at businesses instead of consumers, said Mark D’Arcy, chief creative officer at Facebook.

An early example of the approach is the company’s “Facebook More Together” ad, created by Wieden + Kennedy, which launched two months ago and encourages people to join groups for meaningful experiences.

The company plans to tell stories in similar ways for its other brands. For example, a campaign for Instagram would likely present the photo-sharing app as a way for users to express themselves. Some campaigns, including Instagram’s, likely won’t be shown until next year, when Facebook and its agencies will have had time to test different concepts, Mr. Lucio said.

“Our objective is to build brands that stand the test of time. We’re experimenting and starting from scratch in each market,” he said. “On the direct-to-consumer side, we have never had an effort of this magnitude.”

The company hired Wieden + Kennedy to support the Facebook App, Publicis Groupe SA’s Leo Burnett to handle Facebook Messenger, WPP PLC’s Ogilvy to support Instagram, and Omnicom Group Inc.’s BBDO to work with WhatsApp. Droga5, which was recently acquired by Accenture Interactive, will work on the corporate brand and the broader mission to rebuild trust.

Compared with other digital companies, Facebook has spent less on consumer marketing, Mr. Lucio said, adding that the so-called apology campaign was more of a tactical response to events than a strategic effort to build a brand.

“We have not been able to build our brands directly to the consumer since the company started its journey, contrary to Google that’s been having direct-to-consumer communication for the last 10 years,” he said.

Facebook does trail some big rivals when it comes to ad spending. According to Kantar’s estimates, Amazon spent $1.84 billion on U.S. ads last year, making it the fifth-largest advertiser in the country. Google spent $660 million in 2018, Kantar said. (The Kantar figures don’t include some digital ad spending.)

Agency Diversity

Facebook will require its agencies to assemble diverse teams with more women, people of color and people with diverse sexual orientations, said Mr. Lucio, who joined the company last summer.

The diversity effort echoes Mr. Lucio’s earlier work at HP Inc., where he demanded that the company’s advertising agencies add more women and minorities.

Mr. Lucio lauded the diversity of his own team, but Facebook continues to push for a better mix.

The company last summer said the proportion of women at the company had increased to 36% from 31% in 2014, while the proportion of black employees doubled to 4%, and that of Hispanic employees rose to 5% from 4%.

“We need the client to be diverse, the agencies to be diverse and production houses to be diverse to deliver a product that actually resonates with the consumer,” said Mr. Lucio.

Write to Alexandra Bruell at alexandra.bruell@wsj.com

Corrections & Amplifications

The chief creative officer at Facebook is Mark D’Arcy. An earlier version of this article misspelled his first name as Marc. (June 14, 2019)