Tironian notes are a form of thousands of signs that were formerly used in a system of shorthand dating from the 1st century BCE and named after Tiro, a personal secretary to Marcus Tullius Cicero, who is often credited as their inventor. Tiro's system consisted of about 4,000 signs, extended to 5,000 signs by others. During the medieval period, Tiro's notation system was taught in European monasteries and expanded to a total of about 13,000 signs. The use of Tironian notes declined after 1100 but lasted into the 17th century. A few Tironian signs are still used today.

Marcus Tullius Tiro was first a slave, then a freedman, of Cicero from whom he received his nomen and praenomen. He is frequently mentioned in Cicero's letters. After Cicero's death Tiro published his former master's collected works of letters and speeches. He also wrote a considerable number of books himself, and is thought to have invented an early form of shorthand.