If you're struggling to get your résumé seen, use this tip from Shark Tank's Kevin O'Leary to make it stand out.

• Kevin O'Leary said he hires people who have hobbies that contrast with the professional skills required.
• "It's important because it shows that the person is balanced," he told CNBC Make It.

It can be hard to get your résumé seen by recruiters. But Kevin O'Leary, the legendary investor and star of Shark Tank, has some advice that might help.

O'Leary told CNBC Make It about the traits he looks for when trying to fill a role. One 'green flag' he highlighted is when candidates have a hobby or pastime that is "completely different" and "polar" to the professional skill set he's seeking.

"It's very important because it shows that the person is balanced in the sense of how they think," O'Leary told the publication.

He said that he likes candidates who have a "yin and yang" and are well-rounded as a person. For example, someone who's good with finances but also enjoys playing a musical instrument.

O'Leary said that he hired somebody for a social media role after he learned that she was also a ballet dancer. He said that it's a good sign when a candidate is dedicated to a potentially time-consuming hobby because it shows they're a diligent worker.

"When I see people that are balanced that way, it doesn't mean they're not working very hard — they are. They're working like crazy because they're trying to do all these things at the same time," he told CNBC Make It.

O'Leary co-founded SoftKey in the eighties but gained fame for appearing on TV shows Shark Tank and, more recently, Money Court. He's chairman of investment fund O'Shares Investment Advisers.

He regularly shares tips for climbing the career ladder. He previously told the podcaster Dan Schawbel that his greatest career advice is to have balance.

While it's always important to ensure that you tailor your résumé to include skills that are relevant to the role for which you're applying, recruiters say that it's important to have notable achievements or hobbies that will make it stand out.

Katy Ingle, Bank of America's head of diversity and inclusion for Europe, Middle East, and Africa previously told Insider that she asks candidates to tell her about their hobbies outside of work because it shows her what they can bring to the role.