German-born American cofounder, with Eberhard Anheuser, of the firm later to be known as Anheuser-Busch Companies, Inc., one of the largest breweries in the world.

Busch was the youngest of 21 children born to Ulrich Busch, a wealthy dealer in wines and brewer's supplies. Adolphus emigrated to the United States in 1857, settling in St. Louis, Missouri. With an inheritance, he established his own brewer's supply company, and in 1865 he entered the brewing business with his father-in-law, Eberhard Anheuser; he became a partner in 1873. That same year Busch discovered a means of pasteurizing beer so that it could withstand temperature fluctuations, enabling the firm to distribute its beer on a nationwide basis. By 1901 the Anheuser-Busch Brewing Association (as the company had been called since 1879) had surpassed its rival Pabst and was selling more than one million barrels of beer a year, making it the United States' largest brewery.

Busch was known as an astute marketer. Working with Carl Conrad, a St. Louis restaurateur, he developed a light beer called Budweiser in the belief that consumers would prefer it to the dark brews then prevalent. Budweiser thereafter became the world's best-selling beer.

Upon Busch's death, the company was inherited by his eldest son, August, whose heirs retain a substantial interest today.