List of Famous people born on October 21st

Giuseppe Giacosa was an Italian poet, playwright and librettist.

Albert Abram Aftalion was a French economist.

Napoléon Henri Reber was a French composer.

Shri Krishna Sinha, also known as Shri Babu, was the first chief minister of the Indian state of Bihar (1946–61). Except for the period of World War II, Sinha was the chief minister of Bihar from the time of the first Congress Ministry in 1937 until his death in 1961. Along with the Desh Ratna Rajendra Prasad and Bihar Vibhuti Anugrah Narayan Sinha, Sinha is regarded among the 'Architects of Modern Bihar'. He also led the Dalit entry into the Baidyanath Dham temple, which reflected his commitment towards the upliftment and social empowerment of the Dalits. He was the first chief minister in the country to abolish the zamindari system. He underwent different terms of imprisonment for a total of about eight years in British India. Sinha's mass meetings brought hordes of people to hear him. He was known as Bihar Kesari for his lionlike roars when he rose to address the masses. His close friend and eminent Gandhian Bihar Vibhuti A.N. Sinha in his essay Mere Shri Babu wrote that, "Since 1921, the History of Bihar has been the history of the life of Shri Babu".

Thomas Noel Hill, 2nd Baron Berwick of Attingham, FSA, was a British peer and art patron.

Ernst Emil Alexander Back was a German physicist, born in Freiburg. He attended school in Strasbourg until 1900, and from 1902 until 1906 studied law in Strasbourg, Munich, and Berlin. He then worked in the legal profession in Alsace-Lorraine until 1909, afterwards taking leave to study physics in Tübingen. He retired from the legal profession in 1912, and earned his Ph.D. in 1913. His thesis, titled Zur Prestonschen Regel, was on the subject of what would later be called the Paschen-Back effect, and was named after Back and Friedrich Paschen.