The National Football League is adding Reddit Inc. to its roster of digital marketing channels as its new season begins, hosting a series of “Ask Me Anything” discussions on the platform as part of a broader content and advertising deal.

Current and former NFL players, league executives, team personnel, famous fans and others associated with the league will take questions from Reddit users in the discussions, a popular Reddit format abbreviated as AMAs.

The NFL will also produce digital video series featuring the guests, to be distributed on Reddit as well as on the NFL’s social media channels, NFL.com and cable TV’s NFL Network, the league said.

The NFL isn’t paying Reddit a fee, but the companies will share any revenue generated by sponsorships for the videos, according to people familiar with the matter.

Although the NFL remains TV’s most popular property, the league is keen to bolster its appeal, including among young people. Earlier this week, the league announced a multiyear partnership with social media video app TikTok to share highlights and other social videos.

According to 2018 Comscore data cited by Reddit, 17% of Reddit users don’t use Facebook, 28% don’t use Twitter, 33% don’t use Instagram and 43% don’t use Snapchat. That was a compelling pitch, said Blake Stuchin, vice president of digital media business development for the NFL.

Reddit’s AMAs are open forums where users can post questions, which can then be selected and answered by the guest. Users have the option to “upvote” a question they like, which makes it more visible to the guest and more likely to be answered.

Reddit users don’t hesitate to post Ask Me Anything questions about controversial topics—which for the NFL could include player safety, officiating, how the league handles incidents with players off the field and social-justice issues.

The league will largely leave those questions to the AMA guests to address if they want to, Mr. Stuchin said.

“Generally, the participants will be representing themselves, first and foremost, and not necessarily the views of the NFL,” Mr. Stuchin said. “But the bulk of the conversations we have seen on Reddit—and the bulk of what people generally want to talk about—is core football. Anything beyond that, it’s really no different than the comments we see on any user-generated or social platform.”

The NFL plans a minimum of one AMA a month over the season but expects that number to grow, Mr. Stuchin said. Former Chicago Bears wide receiver Devin Hester, NFL Network reporters and the NFL’s research team have hosted AMAs under the program so far.

Reddit says it has 8.8 million visitors to its football communities on the platform each month. The main NFL forum has 1.4 million members, with each team also having at least one dedicated forum on the platform.

The video series will also serve as a type of marketing for Reddit as the league distributes them widely, said Alex Riccomini, senior director of business development and media partnerships at Reddit. “We are thinking of ways to help introduce Reddit to new users off platform,” Ms. Riccomini said.

Write to Sahil Patel at Sahil.Patel@wsj.com