Dartford have made their fourth new signing of the summer.
Left-sided defender Tyrone Sterling, 25, is making the step up to Conference Premier football after ending last season with Dover Athletic.
Darts boss Tony Burman told the club's website: "I have been impressed with Tyrone's desire and commitment to play at Dartford FC for the right reasons and to have the opportunity to play at a higher level."
Sterling spent seven years with Cray Wanderers and he was also taken on trial by Dagenham & Redbridge.
In January, he became the first signing of Chris Kinnear's second spell in charge at Dover.
Dartford have already brought in goalkeeper Alan Julian, defender Kenny Clark and midfielder Max Cornhill this summer.