Sefer Reis (Ottoman Turkish:سفر) (died 1565) was a Turkish privateer and Ottoman admiral who was active against the Portuguese in the Indian Ocean in the 16th century.
There is almost nothing known about Sefer Reis' origin and family background. The only thing scholars know is that he was of Albanian origin. The strategy of Sefer Reis was different from that of his predecessors in that he never tried to storm a fortress, transport troops or land siege equipment. From hard years of experience, he knew that the strength as well as the weakness of the Portuguese lay in the sea, and he concentrated his operations on Portuguese ships so that his victories were not measured in hectares of conquered territory, but in captured vessels and increased custom revenues in Mocha, Jiddah and Suez.
In 1560, the Ottoman governor of Egypt Sofu Hadım Ali Pasha blocked the reappointment of Seydi Ali Reis to the rank of admiral after his long journey back from Aceh, which was being pushed by Rüstem Pasha. Instead, Sefer Reis was promoted to the supreme command of the Ottoman Empire's entire Indian Ocean fleet.