The deal, reportedly to be announced this week, is believed to be the biggest annual endorsement agreement in world football.
The Ronaldo agreement will add to the £300m kit arrangement the sportswear manufacturer already has with newly crowned Premier League champions Manchester United, who retained their title at the weekend.
The Portuguese international striker and current world footballer of the year is one of the highest profile and commercially appealing players in the world. He recently signed a deal to become a global ambassador for motor oil company Castrol, which will see the player fronting campaigns for the Castrol Edge and Castrol Power 1 brands
The Nike deal is also being seen as an indication of where Ronaldo intends to be playing his football next season. The player has long been courted by Spanish club Real Madrid, who have a kit deal with rival brand Adidas.