The teenager, who sang with male choir Only Boys Aloud on the popular ITV show, was diagnosed with bone cancer in July 2014.
After battling Ewing Sarcoma for over a year, Ryan Howell collapsed at home in August.
Struggling for breath, the young singer later died from a collapsed lung.
He passed away in his mum’s arms.
Speaking to Wales Online about her beloved son, mother Donna said: “He liked to make people laugh. That was his goal. He had an infectious smile.
“He would put a smile on your face. He was the best son I could have ever had.”
The official Only Boys Aloud account also paid tribute to Ryan on Twitter.
They wrote: “We were deeply saddened to hear the news about Ryan. Our thoughts go out to his friends and family.”
Team captain Aled Powys Williams also paid his respects to Ryan on the social networking site in Welsh and English.
He wrote: "A lovely lad. Cysga'n dawel Ryan / RIP Ryan"
Fellow members of the Only Boys Aloud choir, the act that finished third in the 2012 BGT, gave a performance on Saturday and dedicated it to Ryan.
Our thoughts are with Ryan Howell’s friends and family at this sad time.