The 27-year-old, who played alongside Brazlian and Paris Saint Germain superstar Neymar at Brazilian club side Santos in 2012, has signed as an injury replacement for marquee Rodrigo Vargas to bolster the high flying Jets' attacking stocks.
Rodriguez joins Newcastle after a two-year stint at Greek Superleague club AEK Athens where he played alongside Vargas.
Newcastle Jets CEO Lawrie McKinna revealed the club had been in negotiations with Rodriguez for "quite a while" as they searched for a player to cover for Vargas who is not expected to return to action until March after breaking his ankle during the Jets 2-1 win against Brisbane on October 22.
Rodriguez was reportedly close to joining Newcastle in September, but Jets coach Ernie Merrick's preference for a traditional number 10 led to the club inking the signature of Venezuelan attacking midfielder Vargas to a one-year marquee deal.
The diminutive Rodriguez, who stands at 172cm, is an attacking player who can operate centrally or on the left wing.
He has made 27 appearances in the Greek Super League for AEK over the past two seasons and has a strong pedigree in South America.
Jets’ boss, Ernie Merrick said that his injured midfielder Vargas played a significant part in securing the club’s latest signing.
“Ronny was speaking with Patricio regularly, talking about what a great town Newcastle is and how much he’s been enjoying his time here,” said Merrick.
“They’ve played together quite a bit, so I think that will be a massive advantage for us when we have them both on the park together later this season.
“Patricio is a very good one-on-one dribbling type player that knocks in great crosses, he’s technically very strong and has great speed.
“I’m keen to get him into more goal scoring opportunities, he’s a wonderful striker of the ball and will add a great deal to our front third.”
“He’s got all the characteristics of an Argentinian player, he’s strong, resilient and knows how to win a game.”
Rodriguez began his career with top-flight Argentinian side Independiente, playing 87 times before shifting to Santos for the 2012 season where he played alongside Neymar.
Rodriguez is not expected to arrive in Newcastle until a few days before the A-League transfer window officially opens on January 3.
His first game for the club is most likely to be the Jets derby clash with fierce rivals Central Coast Mariners on January 9.
The signing of Rodriguez is the club's second January transfer acquisition after securing 19-year-old rising star Riley Mcgree on a loan deal from Belgium's Club Brugge.
The Jets are set to continue their transfer window spending spree with the club also in the market for an injury replacement for star striker Roy O'Donovan who has been sidelined until march with a groin injury.