Ali Bitchin (c. 1560 – 1645; sometimes spelt "Bitchnin") was a "renegade" (Christian converted to Islam) who made his fortune in Algiers through privateering. Bitchin was believed to be born with the family name of Piccini or Puccini or Piccinino in Venice. He was a Grand Admiral of Algiers and is known for the Ali Bitchin Mosque he built in the district of Zoudj-Aïoun in the old city (Casbah). He was the de facto governor of Regency of Algiers from 1621 to 1645.

Bitchin became particularly well known through the captivity narratives published by Emanuel D'Aranda, his slave for about a year from 1640 to 1641.

Bitchin was part of a group of people captured in 1578, by Hassan Veneziano the Beylerbeys of Algiers at the time, while aboard a Venetian ship. Bitchin, only a ten-year-old boy at the time, was bought from the Babel Boustan slaves market (current fishery) for 60 golden dinars, by the Raïs Fettah-Allah Ben-Khodja, from whom he learned privateering.

With the exception of Raïs Hamidou who lived in the late 18th century, no pirate was as influential in North African history as Ali Bitchin. Under his command, the Algerian Navy assured her supremacy over the Mediterranean, blithely crossing the Straits of Gibraltar and pushing all the way to the Arctic Circle. Bitchin's privateers attacked Madeira, entered the Atlantic Ocean and even reached Ireland. They often attacked heavier vessels from their light boats regardless of the number of enemies. They resisted the most violent storms, appeared unexpectedly, and taunted their enemy with their wild audacity.

From the 1620s, he was the supreme head of the Ta'ifat al-Ra'is (guild of corsairs), and took on the title Captain of the Sea. He managed to maintain an equilibrium of stability between the interests of the corsairs, the janissary corps and the merchant class who invested money in the raids. Under his command, his fleet took the ships of nearly every European nation, he raided coastal settlements across the Meditteranean and from the Atlantic to the Albanian coast. He was also responsible for losses from English shipping in 1639 that exceeded the total losses from 1629 to 1638 combined.

By the late 1630s and early 1640s his reputation began to wane, especially in the Battle of Valona in 1638, where his combined Algerian and Tunisian fleet was decimated, losing 16 galleys and about 100 slaves. Senior leaders blamed him and he was sentenced to death but was quickly pardoned. He was also sidelined by the Ottoman court under Ibrahim I when he refused to partake in the Ottoman war against the Venetians.

Tradition says that when Ali Bitchin saw Princess Lalla Lallahoum, the daughter of Ben Ali, Sultan of the Kabyle people of Algiers, for the first time, he could not resist the desire to love her; she was considered the most beautiful woman of all. All his senses were troubled, and his days restless. Accompanied by Lalla N'fiça, widow of his mentor, Raïs Fethullah Ben-Khodja, Bitchin went to Ben Ali seeking the hand of his daughter.

Bitchin placed at the foot of the beautiful princess carpets of Persia, silks and brocades of the Levant, diamonds from India, Peru's gold and much more. Lalla Lallahoum regarded with indifference these riches: "No, she said, I have nothing to do of all this, I demand that my suitor build a mosque to prove his faith". Ali Bitchin Mosque was built that same year, in 1622.