Setelah kehilangan istrinya tujuh tahun sebelumnya, Dr. John Dolittle (Robert Downey Jr.) yangdokter hewan terkenal di Queen Victoria's England, mengasingkan diri ke Dolittle Manor dengamembawa hewan eksotisnya. Tetapi ketika ratu muda (Jessie Buckley, Wild Rose) jatuh sakit parah, Dolittle terpaksa berlayar dan melalui petualangan hebat ke pulau mitos untuk mencari obat, mendapatkan kembali kecerdasan dan keberanianya saat bertemu musuh lama dan menemukan makhluk yang luar biasa. Dokter tersebut bersama anak muda yang sedang magang (Dunkirk's Harry Collett) dan sejumlah teman-teman hewan, termasuk gorila , bebek, burung Unta, beruang kutub, dan burung beo yang menjadi penasihat dan sosok paling di percaya Dolittle.

After losing his wife seven years earlier, the eccentric Dr. John Dolittle (Robert Downey Jr.), famed doctor and veterinarian of Queen Victoria's England, hermits himself away behind the high walls of Dolittle Manor with only his menagerie of exotic animals for company. But when the young queen (Jessie Buckley, Wild Rose) falls gravely ill, a reluctant Dolittle is forced to set sail on an epic adventure to a mythical island in search of a cure, regaining his wit and courage as he crosses old adversaries and discovers wondrous creatures. The doctor is joined on his quest by a young, self-appointed apprentice (Dunkirk's Harry Collett) and a raucous coterie of animal friends, including an anxious gorilla (Oscar (R) winner Rami Malek), an enthusiastic but bird-brained duck (Oscar (R) winner Octavia Spencer), a bickering duo of a cynical ostrich (The Big Sick's Kumail Nanjiani) and an upbeat polar bear (John Cena, Bumblebee) and a headstrong parrot (Oscar (R) winner Emma Thompson), who serves as Dolittle's most trusted advisor and confidante.