Almost 15 years after making magic by bringing together Niall Horan, Liam Payne, Harry Styles, Louis Tomlinson and Zayn Malik as a group on "X Factor," the record executive is searching for "future megastars" who are ready to put in the work to achieve international fame.

Simon announced his new project Tuesday, dropping recruitment billboards across London, which read ... "Simon needs you! Future megastars wanted for new boyband. No timewasters."

The former "American Idol" judge explained his reason for the new endeavor, noting there hasn't been an impactful boy band since 1D -- and he isn't wrong, FWIW.

He added ... "The industry tends to focus on solo artists – so it usually takes someone from outside to put a group together. Nothing beats the fun of being in a group, touring the world and performing for thousands."

SC plans to start auditioning for talent this summer, with the first casting call taking place in Newcastle, England on July 4. Other auditions will take place in Liverpool, Dublin and London.

Although, Simon did note there might be some risk with the project ... since the last non-K-Pop group to really take off was Little Mix, and they went on hiatus in 2022.

One Direction had its own highs and lows, with Zayn notably leaving the band in 2015, leading the group to go on hiatus a year later. Nonetheless, the fellas saw quite a bit of success after leaving 1D ... with each launching their own solo careers.

Yet, there's no denying Harry emerged as the group's biggest alum -- winning 3 Grammys over the last several years.

Simon is definitely using Harry's legacy to his advantage, noting his new boy band is "a brilliant launchpad for a solo career."