The pair have teamed up to create new clothes that merge country designs with chic streetwise attire.
Timberlake says, "This clothing is representative of where we come from - it's sort of country, but it's also got a little edge and a little chic to it."
The line, which will launch exclusively at US department store chain Bloomingdales in November (05), is called William Rast after Timberlake and Ayala's grandfathers.
Timberlake explains, "We just kind of picked the two people who are most influential in our lives, and that's our grandfathers. William is my grandfather's first name and Rast is Trace's grandfather's last name."
Ayala, fiance of actress Elisha Cuthbert, adds, "My grandfather and Justin's grandfather knew each other growing up. They still live down the road from each other."