Aicher was a classmate and friend of Werner Scholl, and through him met Werner's family, including his siblings Hans and Sophie Scholl, both of whom would be executed in 1943 for their membership in the White Rose resistance movement in Nazi Germany. Like the Scholls, Aicher was strongly opposed to the Nazi movement. He was arrested in 1937 for refusing to join the Hitler Youth, and consequently he was failed on his abitur (college entrance) examination in 1941. He was subsequently drafted into the German army to fight in World War II, though he tried to leave at various times. In 1945 he deserted the army, and went into hiding at the Scholls' house in Wutach.
In 1952 he married Inge Scholl, the older sister of Werner, Hans and Sophie.
In 1953, along with Inge Scholl and Max Bill, he founded the Ulm School of Design (Hochschule für Gestaltung Ulm), which became one of Germany's leading educational centres for design during the 1950s and 1960s.
He was heavily involved in corporate branding and designed the logo for Lufthansa Airlines in 1969.
Aicher may be best known for being the lead designer for the 1972 Munich Olympics. He created a new set of pictograms that paved the way for the ubiquitous stick figures currently used in public signs. He also created the first official Olympic Mascot, a striped dachshund named Waldi.
In 1980, Otl Aicher became a consultant of the kitchen company bulthaup. He created the rotis font family in 1988, naming it after the domicile of Rotis in the city of Leutkirch im Allgäu, where Aicher lived and kept his studio which is still used today by bulthaup.
He has also designed the logo of Munich Airport which is just the letter " M " in a special font.
Aicher died on September 1, 1991, after being struck in a traffic accident.