In the German Qualifier for the 2015 World Championship, Hopp beat Sascha Stein 10–8 in the final but subsequently qualified through the Pro Tour Order of Merit to begin the tournament in the first round, instead of the preliminary round. He produced a superb performance against Mervyn King to beat him 3–2, sealing his place in the second round with a 161 finish. Hopp hit 10 180s during the match, the most of all the first round players in the event. He was comfortably defeated 4–0 by Vincent van der Voort in the second round. However, his play during 2014 and at the World Championship saw him rise 14 places in the rankings during the year to start 2015 62nd, the first time Hopp has been inside the top 64 who gain their PDC tour cards. At the first UK Open Qualifier he eliminated Kevin Painter, Ian White and Michael Smith to play in his first quarter-final in the PDC, where Brendan Dolan beat Hopp 6–5. This result helped him enter the UK Open at the third round stage where Kim Huybrechts beat him 9–7 after Hopp had been 7–5 up. Hopp played in his first World Cup of Darts this year. He partnered Jyhan Artut and they saw off India and Austria to make the quarter-finals, where they lost both their singles matches against England to exit the tournament. He was invited to play in the inaugural World Series of Darts Finals and saw off Dimitri Van den Bergh 6–3, before losing by a reversal of this scoreline to Peter Wright in the second round. In the final of the 2015 World Youth Championship, Hopp was never ahead of his opponent Nathan Aspinall until the final leg when he sealed the title with a 6–5 win.