McLaren will switch to BP/Castrol fuel and lubricants for the 2017 Formula 1 season.
The team's long-standing relationship with Exxon/Mobil concluded at the end of last year, with the oil company joining F1 rival Red Bull in 2017.
McLaren had long been expected to join forces with BP/Castrol, with the move made official on Friday.
"This agreement between McLaren, BP and Castrol is between brands who both share a long-standing and well-recognised passion for innovation in all we do," McLaren Technology Group's CEO Jonathan Neale.
"Our McLaren-Honda team provides a global platform for Castrol to supply bespoke advanced lubricant technology."
BP/Castrol, returning to Formula 1 this year, had already announced a deal to work with Renault.
It will also supply lubricants and oil to McLaren's automotive branch.