Professional Darts Corporation chief executive Porter landed the same role with the O's under Barry Hearn in 2006.
The 37-year-old left the National League side in October 2014, following Francesco Becchetti's takeover.
"This is a time for us to look to the future and there's a great buzz around the place," he told the club website.
"Everyone knows how difficult things have been and that cloud has now been lifted."
Leyton Orient have appointed former chief executive Matt Porter to their board of directors following Nigel Travis' takeover on 22 June.