Turley, 26, had spells with non-league Salisbury City and Forest Green before joining Eastleigh in 2014 where he made 49 National League appearances.
"I'm delighted to be finally making the step up to the Football League and I want to take full advantage of this opportunity," he told the club website.
"I'm a quick and aggressive player, your typical centre-half really."
Manager Warren Feeney hopes Turley, who turned down an improved deal at Eastleigh to join the Exiles, is the first of several summer signings.
"We know exactly what we want in terms of mentality and ability," Feeney told BBC Wales Sport.
"It might take a few weeks, but we are confident of putting a very competitive squad in place."
Newport have offered contracts to eight members of last season's first team, but Feeney is unconcerned that none of the players are yet to agree to a stay at Rodney Parade.
"It is not an issue at this stage," he said.
"We won't let it drag on and on and I've made that clear to the players."
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Newport County have signed defender Jamie Turley on a two-year deal from National League side Eastleigh.