Joe Quigley, who most recently was under contract at Bromley, joins Peter Taylor's side on a two-year deal.
"I'm buzzing to get it sorted," he told the club's website. "It's been something I've known about for a while, it was a no-brainer."
Having come through the youth set-up at Bournemouth, Quigley has played for a host of National League clubs including Maidstone, Boreham Wood, Eastbourne Borough and Havant & Waterlooville.
Now 22-year-old, Quigley says he is hoping to put down some roots in East London.
"I've played in this league now since I was 18 so I'm fairly used to it," said the Irishman.
"Hopefully I can get settled in quick and help Dagenham & Redbridge get some success.
"I want to come here and settle down here. I want to be a Dagenham & Redbridge player for my whole contract and get some success."