All but around £1 million of the income comes from adverts shown before videos, with the rest from sponsorship deals.
That is exactly double what Ryan made in the previous year, according to Forbes, when he was placed eighth in the 2017 list.
Asked by NBC why kids liked watching his videos, Ryan - who is now eight - replied: "Because I'm entertaining and I'm amusing".
The remaining $1 million came from sponsored posts.
Since launching his main channel in 2015, Ryan has amassed more than 17m followers and almost 26bn views.
While Jake Paul moved up six places to second, his brother Logan Paul has tumbled down the Forbes rankings this year to 10th place with $14.5m - still $3m more than 2017.
Ryan, whose last name hasn't been made public to protect his identity, beat top YouTubers such as Logan Paul, Felix Kjellberg (PewDiePie fame) and Markiplier.
Ryan's parents are reportedly putting 15 percent of his earnings away into a bank account until he is a legal adult. In his most popular videos, he's seen opening up giant eggs to find toys from Disney's Cars and Paw Patrol.
The store, in August, began selling a wide range of toys and clothing called Ryan's World, and a video showing him and his parents searching for his own toys at a Walmart store has had 14 million views in three months.
Of course, RyanToysReview isn't the sole property of seven-year-old Ryan, himself - the channel is run by his mother and father, who also appear in his videos, along with his twin sisters. Meanwhile, makeup guru Jeffree Star slid into fifth place with total earnings of $18 million for the year.