Tsarevich Alexei (Aleksey) Nicolaievitch of Russia (August 12, 1904 - July 17, 1918), or Alexis Nicholaievitch, of the House of Romanov, was a Tsarevich of Russia and was the youngest child of Tsar Nicholas II of Russia, out of five children.

Alexei was closest to Anastasia out of all of his sisters.

He had a medical condition called hemophilia from his mother, Alexandra and traced back to Victoria of the United Kingdom.

He was assassinated along with the rest of his family in 1918. His body was missing, along with a Grand Duchess (Tatiana, Maria or Anastasia) when the bodies were found.