The 'Read All About It' rapper told Heat that he was no fan of the 2010 X Factor winner's music.
Asked who annoyed him in music, Green replied: "Matt Cardle. Have you heard his f**king single?
"I don't know him from Adam so I haven't got any kind of personal problem with him, but his music is f**king horrendous."
Green is poised to land his first UK number one single this weekend with his new track, which he performed on Sunday evening's X Factor results show.
Asked if he cared if people liked his own work, Green added: "It's easier when they don't.
"I wouldn't want everyone not to like me, but I don't do stuff in the hope that people like me. Because that sounds contrived, doesn't it?"
Earlier this year, Green said that he wanted to work with girl band Parade because they are "pretty girls with s**t songs".
> Matt Cardle confirms new single 'Starlight', thanks fans for support
Watch the Matt Cardle 'Run For Your Life' music video below: