OSTROLEKA (Pol. Ostrolęka; also Ostrolenka), town in Warsaw province, Poland. A permanent Jewish settlement in Ostroleka is not recorded before the 19th century, although Jews are mentioned in connection with the town in a document of 1622. An ordinance of 1826 prescribed certain areas for Jewish residence, only those with special privileges being permitted to live outside. The restriction was removed in 1862. The community, which numbered approximately 560 in 1827 (16.3% of the total population), increased to 1,129 (36.8%) in 1856; 4,832 (37.2%) in 1897; and 6,219 (53.5%) in 1909; decreasing to 3,352 (36.6%) in 1921. The 708 members of the loan society (founded in 1909) of the Ostroleka community in 1924 comprised 359 artisans, 259 small traders, 11 agriculturalists, and 79 members of other professions.
Sefer Kehillat Ostrolenka (Heb. and Yid., 1963).