Evans, who will join Portland's financial communications team, brings more than 15 years of experience consultancy, journalism and banking.
He has advised and helped manage the corporate reputations of listed companies, private equity firms, pension funds, asset managers and banks. This includes advising on a range of high-profile M&A transactions, corporate restructurings, activist situations and litigation processes.
"It’s great to have Simon on board as part of the growing financial communications team here at Portland. He joins at a time of real change," Portland partner Steffan Williams said.
"The days of financial communications being a standalone discipline are over – it needs to sit at the heart of an integrated communications offer that includes ongoing corporate communications, public affairs and regulatory understanding, and digital targeting. We look forward to announcing further hires to the team in 2020."
Evans joins from Kekst CNC, where he was a director in its London office, and has previously held senior roles at Capital MSL and Weber Shandwick, where he was head of business media.
Earlier in his career he was deputy business editor at the Independent on Sunday and a senior correspondent at newpaper City AM, Citywire and Euromoney’s International Securities Finance publication.
Evans also worked as an equities trader at investment bank Lehman Brothers, working in the firm's equity finance unit.
Portland has undergone a leadership change in recent months, with founder Tim Allan leaving the business and Mark Flanagan becoming chief executive.
The consultancy is one of PRWeek's nine agencies to watch in 2020.