YouTube is tapping into old media to push geeky Internet videos.

In its biggest traditional media campaign to date, YouTube plans to run TV and in-theater advertising to promote next month’s “Geek Week,” aiming to drive young auds to a range of sci-fi, superhero, cosplay, animation and other nerd-skewing content across 100-plus channels.

The Google-owned Internet video site isn’t disclosing a dollar figure for the Geek Week campaign, which is in part aimed at deflecting criticism that YouTube doesn’t adequately market on behalf of its content partners.

With the Geek Week push, “what we’re trying to do is really focus on the under-35 audience, with high reach and frequency,” YouTube marketing veep Danielle Tiedt said.

YouTube’s weeklong “celebration” of geek culture will run Aug. 4 to 10, during which dozens of content partners are set to debut new videos, series and special events on their channels.

The media campaign will include in-theater ads kicking off this weekend across theater chains tied to major summer releases. Next week, “Geek Week” promos will air on broadcast and cable networks geared toward reaching younger auds.

As an umbrella category, geek videos are huge on YouTube, accounting for 11 of the top 20 non-music channels and generating nearly 60 billion views in the last 12 months, according to the company. “We are doing this because we see there’s never been a better time to be a geek,” Tiedt said.

Featured Geek Week partners will include Stan Lee of World of Heroes; Machinima and Maker StudiosPolaris network; Felicia Day of “Geek & Sundry”; Freddie Wong, who is launching “Video Game High School 2” YouTube series on July 25; and YomYomF, who will host a celebration of geekery from around the world, including all things “Doctor Who.”

YouTube is still determining media schedule for the Geek Week ads. The site ran TV spots for the similar Comedy Week campaign in May, with buys on MTV, Comedy Central, the NBA playoffs and specific shows including The CW’s “Vampire Diaries” and “Arrow,” NBC’s “The Voice,” and Fox’s “New Girl.”

The Geek Week campaign also will encompass Twitter and Facebook, but YouTube isn’t buying marketing messaging on those platforms: “We have enough of a base to engage directly,” Tiedt said. YouTube has about 76 million fans on Facebook and 30.9 million followers on Twitter.

With its plethora of partners, YouTube is never going to be able to market all of the content on the website, Tiedt said. “What we are trying really hard to do is connect people to the channels they love and help our partners get more exposure.”

YouTube’s Geek Week is produced in conjunction with Legendary Entertainment’s Nerdist Industries in the U.S. and Channel Flip in the U.K. More info on the week’s programming lineup will be available at youtube.com/geekweek.