The day was created to bring awareness to the number of dogs who need forever homes.
Some tips on how to adopt safely include adopting from a rescue or shelter.
The BBB says the Facebook Marketplace is also safe since Facebook has banned puppy mills from advertising.
Need a pick-me-up? Don’t miss out on this National Puppy Day cuteness
Ready for cuteness overload? Thursday is National Puppy Day, and there is no shortage of adorable pups to spread smiles.
It’s a day to “celebrate the magic and unconditional love that puppies bring to our lives,” according to the National Puppy Day website. And it’s a day to “help save orphaned puppies across the globe” and spread awareness about puppy mills, nationalpuppyday says.
Betty White, Sarah Michelle Gellar, more Hollywood celebs honor National Puppy Day
"He may be 12, but he's my baby!! Happy #NationalPuppyDay!" she wrote.
But White, 95, was hardly the only Hollywood star to share a pic of their cute canine.
"Buffy the Vampire Slayer" star Sarah Michelle Gellar, 39, shared a throwback photo of her and hubby, Freddie Prinze Jr., 41, cuddling with their Bernese mountain dog when the dog was just a pup.
"Fuller House" star Lori Loughlin, 52, shared a bedtime snap of her lovable pooch, captioning it, "When you get out of bed to get a glass of water and somebody takes your spot."
Drew Barrymore, 42, chimed in to share a sweet photo of her beautiful girl, Lucy.
The force is with our furry ones! "Star Wars" star Mark Hamill shared pics of his own dogs, Millie and Mabel, and also included a pic of his "Star Wars" co-star, the late, great Carrie Fisher, with her beloved dog, Gary.
The folks behind "The Voice" Twitter page shared a great GIF of judge Adam Levine, 38, and his goldie Charlie.
"Jane the Virgin" star Gina Rodriguez, 32, honored her pup and her beau, Joe LoCicero, with a sweet, sleepy pic of the pair.
"Waking up to #NationalPuppyDay thinking damn, I am a lucky woman," she wrote in the caption.
"Hamilton" star Lin-Manuel Miranda, 37, remembered the day he rescued his dog, Tobillo, with a special throwback shot.