In 1962, Tony "Tony Lip" Vallelonga (Viggo Mortensen), a tough bouncer, is looking for work when his nightclub is closed for renovations. The most promising offer turns out to be the driver for the African-American classical pianist Don Shirley (Mahershala Ali) for a concert tour into the Deep South states. Although hardly enthused at working for a black man, Tony accepts the job and they begin their trek armed with The Negro Motorist Green Book, a travel guide for safe travel through America's racial segregation. Together, the snobbishly erudite pianist and the crudely practical bouncer can barely get along with their clashing attitudes to life and ideals. However, as the disparate pair witness and endure America's appalling injustices on the road, they find a newfound respect for each other's talents and start to face them together. In doing so, they would nurture a friendship and understanding that would change both their lives.