Just Do It is a slogan used by Nike, a multinational corporation that designs, develops, and sells athletic footwear, apparel, and equipment. The slogan was first introduced in 1988 and has become one of the most iconic and recognizable slogans in the world.
Futura Condensed Extra Black by Paul Renner is the font used for the slogan text. Futura is a commercial typeface and you can view more details about it here.