Barrett said he particularly likes the 33-year-old singer's style and identifies with it, reported Contactmusic.
"I particularly like Justin's personal style. For me, it's like his music, a combination of urban/street with classical, which is the same as my design ethos. It's a hybrid of sartorial elements," he said.
Barrett's suits were last seen on Timberlake during his 20/20 Experience world tour and the pair worked closely together to ensure the outfits looked as cool as they were comfortable.
The designer said his favourite ever song of the 'Rock Your Body' star is dancefloor anthem 'Sexy Back', because 'it is iconic and it makes me grin'.