This is up from the $22 million Kaji earned last year, having become popular in the "unboxing" genre of opening and trying out toys.
His first channel "Ryan ToysReview" launched in 2015, later becoming "Ryan's World," now includes educational videos for kids, such as science experiments.
Kaji, who lives in Texas, has amassed nearly 23 million subscribers and now has toy and clothing lines, as well as a show on Nickelodeon and a deal with streaming service Hulu, according to Forbes.
In second place is "Dude Perfect." The channel, which is now a decade old, shows videos of five friends in their 30s do stunts and break Guinness World Records.
Twins Coby and Cory Cotton, Garret Hilbert, Cody Jones and Tyler Toney took home $20 million in 2019, the same as in 2018, but moved up one place in the rankings this year.
Third on Forbes' list is its newest and youngest entrant, five-year-old Anastasia Radzinskaya, who is said to have become known for the videos her parents posted of her being treated for cerebral palsy.
The Russian-born YouTuber, known as "Nastya" or "Stacy" now posts videos playing with her father and has garnered a reported 107 million subscribers across seven YouTube channels, translated into different languages.
Swedish gamer Felix Kjellberg, known as "PewDiePie," remained in the top 10 despite accusations of anti-Semitism regarding some of the videos he's posted.
The 30-year-old recently said he was taking a break from YouTube as he was "feeling very tired."