Macchio, who starred as Daniel LaRusso in The Karate Kid film trilogy and six seasons of Netflix's Cobra Kai, appeared at the Los Angeles ceremony alongside his co-stars William Zabka and Tamlyn Tomita.
The 63-year-old unveiled his star which lay next to that of the late Morita, who played beloved Mr Miyagi in the film franchise.
"To have this star placed right next to my acting partner from that film, the great Pat Morita, is so meaningful to me, so powerful to me," Macchio said.
"Our partnership is something I always described as a soulful magic of The Karate Kid films, and he is still here today blessing all these stories that are moving forward. I can feel him here.
"It is only fitting I shall remain Miyagi-adjacent until the end of time," he joked.
Co-stars Tamlyn Tomita and William Zabka joined Ralph Macchio for the ceremony in Hollywood. (AP PHOTO)
Macchio thanked those for the "thoughtful placement" of his star, adding: "It means the world to me."
Macchio's breakout role was starring in Francis Ford Coppola's 1983 film The Outsiders, before joining the cast of The Karate Kid a year later and starring in two sequels.
Zabka, who signed autographs for fans dressed in Karate Kid costumes ahead of the ceremony, said he first met Macchio at auditions for the original film in 1984.
"From day one he was a big star and a big talent, but he was Ralph. He was so grounded and so easy to be with. After all these years he hasn't changed one bit," the 59-year-old said.
Zabka, who played Macchio's on-screen rival Johnny Lawrence in The Karate Kid franchise and Cobra Kai, described his co-star as "loveable, sincere, and talented".
"He kicked his way into our hearts in the 1984 movie and literally right through my face," he joked.
"How do you measure a friendship and a relationship of four decades, it is a gift that we get to keep doing this together. I love him like a brother."
The Walk of Fame ceremony comes a day after British rock band Coldplay released a new music video for their song The Karate Kid, starring Macchio.