They’re in honor of United Nations-designated International Day of Happiness next week.
The billboards are the work of The Joy Team, a Vancouver-based nonprofit.
Chief Joy Officer Michele McKeag Larsen said people get a boost from having a happy thought.
“We’ve got billboards, bus shelters, posters up in malls, which is new this year,” she said. “We’ve been putting a smile across America for four years now. And we just keep spreading it out a little bit and hoping that people see a message that inspires them and lifts their day.”
The Joy Team was founded in 2010 with the mission of building community by spreading joy, optimism and inspiration.
Billboards promoting happiness will be up in 28 cities across the U.S. over the next four weeks.
Messages include: “In a world where you can be anything, be happy,” or “Happiness never goes out of style. Make the world a happier place.”