John Roberts Jr. (15 August 1847 – 23 December 1919) was a dominant Welsh professional player of English billiards. He was also a notable manufacturer of billiards cues and tables, and promoter of the sport.
Roberts Jr. lived in the shadow of his father, John Roberts, Sr. for many years, but came into the public eye after his father's retirement, beating Willam Cook 1,200–722. However, Cook would eventually gain superiority over John Roberts Jr.
In 1875, Cook was defeated by Roberts Jr. again and it sparked his dominance of the sport. In 1880, he left for Calcutta, where he set up a billiard table factory. Roberts however was able to concede starts to all opposition, but would not play in Championship matches. This damaged the sport's perception, as everybody perceived him to be champion.
As two variants of the sport, "spot-barred" and "all-in" developed, Roberts came back to the fore, competing in only the "spot-barred" version. In 1884, he broke the spot-barred record break from 309 by Cook, to 360. He developed the top of the table, a method to increase breaks requiring alternating cannons and pot reds that would become the "modern" way of playing the game.
In 1885, Roberts sat at the meeting that formed the Billiards Association, and helped to code a new set of rules for the game of English billiards. Roberts challenged Cook for the title, which he won by default, but then he successfully defended the rematch from Cook to win the title.
William Peall beat Roberts in a match where he was restricted to 100 spots in a break. Peall was the leading "all-in" player in the era. Roberts maintained his spot-barred supremacy, and did not challenge either Peall or Billy Mitchell for the championship. He cited that the public would not enjoy the repetition of the game, a foreshadowing of the eventual decline of the game.
Peall and Roberts both claimed to be champions of the sport, and a match to test their claims proved unnegotiable. After a four-year hiatus, the championship returned when the Billiards Association decided to create two championships, one for all-in, and another for spot-barred. By this stage, Roberts was a successful billiards merchandise producer, and offered the association a venue, table and trophy for the new championship, but refused to play in it.