The Greatest Showman is a 2017 musical film inspired by the life of P.T. Barnum and the creation of the Barnum & Bailey Circus. It stars Hugh Jackman, Zac Efron, and Zendaya, and features original music by Benj Pasek and Justin Paul.
While we couldn't locate an exact match for the font used in the film title, it appears to have been either custom designed or heavily modified. However, the lettering bears a strong resemblance to Dragon EF Italic. There's also a freeware font named The Greatest that imitates the lettering and is likely based on this font.