The Bye Bye Love hitmaker passed away in Burbank, California, aged 74, after suffering complications from chronic obstructive pulmonary disease, and now MCCartney has taken to his website to remember one of his "great heroes".
He writes, "With his brother Don, they were one of the major influences on The Beatles. When John (Lennon) and I first started to write songs, I was Phil and he was Don.
"Years later when I finally met Phil, I was completely starstruck and at the same time extremely impressed by his humility and gentleness of soul. I will always love him for giving me some of the sweetest musical memories of my life."
MCCartney joins the likes of Billie Joe Armstrong and Brian May, who have already offered tributes to the late rock 'n' roll legend.