His responsibilities will include looking after major accounts and developing new business in the south.
Cain worked at Complete FS from 1993 to 2003, before he left to set up a student buy-to-let business.
Tony Salentino, director at Complete FS, said: “We are delighted to have Damian back with us. His experience of the market is second to none and demonstrates our commitment to provide only the best support for introducers as we look to build our business further in 2016.”
Cain added: “Having been involved at the birth of the packager market, in particular Complete, I am excited to be returning at a time when the company is looking to expand its reach in the intermediary market, while maintaining its reputation for market leading service to introducers and lender partners.”