In a joint statement, the two bodies said that the partnership marked "a significant shared commitment to enhancing global tennis".
Since 2021, PIF has invested heavily in a number of major sports industries including setting up the LIV golf tour, a rival to the PGA, and purchasing English Premier League club Newcastle United.
The statement did not give details of the amount of the investment which will see PIF become the official naming partner of the ATP rankings.
PIF will also partner with ATP Tour events in Indian Wells, Miami, Madrid, Beijing and the ATP Finals, in addition to the Next Gen ATP Finals, hosted in Jeddah until 2027.
"Our strategic partnership with PIF marks a major moment for tennis," said ATP chief executive Massimo Calvelli in the joint statement.
"It's a shared commitment to propel the future of the sport. With PIF’s dedication to the next generation – fostering innovation and creating opportunities for all – the stage is set for a transformative new period of progress.”
Last year, the kingdom hosted its first ATP Tour event -- the Next Gen ATP Finals in Jeddah -- along with exhibition matches pitting Novak Djokovic against Carlos Alcaraz and Aryna Sabalenka against Ons Jabeur.
- Anger at WTA bid -
In January Rafael Nadal, winner of 22 singles Grand Slams on the men's side, was named ambassador for the Saudi Tennis Federation.
The latest investment with the ATP follows a Saudi bid to secure the WTA Finals in Riyadh, a move that drew criticism from former women's champions Chris Evert and Martina Navratilova while winning the support of current world No.6 Jabeur.
PIF has reshaped the world of golf by setting up the LIV golf tour as a rival to the PGA.
The first event took place in June 2022, causing a split within the sport that caused LIV-affiliated players to be excluded from the Ryder Cup, PGA tour events and consequently the world rankings.
Reigning Masters champion Jon Rahm joined the LIV tour in December in a deal reportedly worth hundreds of millions of dollars.
However, a framework deal between the PGA Tour, DP World Tour and PIF is now under discussion with a view to ending the stand-off.
It also owns four football clubs in the Saudi Pro League and has spent over $885 million (820 million euros) on some of the biggest names in football to play for its teams.
The kingdom is also set to host the 2034 football World Cup.
But Saudi Arabia has been accused by its critics of "sportswashing" by using sport to improve its international reputation after widespread criticism of its human rights and environmental record.
"Through our collaboration with ATP, PIF will be a catalyst for growth of the global tennis landscape, developing talent, fostering inclusivity and driving sustainable innovation," said PIF's Mohamed AlSayyad.
- Murray 'concerns' -
Former world number one Andy Murray highlighted the commitment from the new partners to "collaborate to elevate the long-term future of tennis".
After he was knocked out of the ATP Dubai tournament on Wednesday, he said: "I don't know exactly what it means by sponsoring the events. I don't know what that will look like.
"One of my concerns is obviously actually more about the investment in lower levels of the game and the grassroots of the sport. I think that's extremely important."
World number four Daniil Medvedev said investment can only be a boost for the sport.
"I think if we can make tennis bigger as a sport, more interesting for people, have more coverage, just in general more people will know tennis, who tennis players are," said the former US Open champion.
"I think it's going to be good."
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© Agence France-Presse