The former Ostrovtzer Shul (Synagogue) is located at 58 Cecil Street and Spadina Avenue in downtown Toronto. It was known as the Beth Haknesseth Hagadol Anshei Ostrovtze. The congregation was founded in 1901, but officially in 1910. The building was a former church which was bought by Ostrowiec immigrants and transformed into a synagogue in 1925. It was later sold in 1966, after the Jewish population shifted to the northern part of Toronto.
Information on the founding members can be found here.
In the early years, the synagogue had 2 fraternal societies:
Ostrovtzer Hilfs Farein
Ostrovtzer Ladies Auxiliary
They did not become independent organizations until much later.
Up to the outbreak of the second world war there were two separate Hilfs Fareinin in Toronto, both having identical aims: the raising of funds for the destitute Jews of Ostrowiec. The two societies merged after the Holocaust, forming a single organization to look after all relief activities They provided extensive aid to Ostrowiec Jews who have turned up in the displaced persons camps and those others who were able to make their way to Israel.
Like the Hilfs Farein, the Ladies Auxiliary was initially a branch of the synagogue, with the members' wives devoting themselves to the welfare of the synagogue. The ladies of the congregation donated the Holy Ark, a "Perocheth" for the Holy Ark; and a Chupah, and also raised money for modernizing the synagogue.
The shul was later amalgamated with the Shaarei Tefilla Synagogue on Bathurst Street in 1985.
The building is now the Cecil Community Centre.
Detailed History of Ostrovtser Shul in Toronto
Ostrowiec Yizkor book, 1971
The Founding Families of the Ostrover Synagogue
by Cyril Gryfe, Shem Tov, the Jewish Genealogical Society of Canada (Toronto), March 2008
Ostrovtzer Shul Jubilee Book
FEB 19, 1950 - Ontario Jewish Archives
An in-depth look at the shul and its history
Wojtek Mazan visits Ostrowcer Shul in Toronto
Link to Wojtek Mazan's blog in Polish describing the history of the Ostrowiec Synagogue on Cecil Street in Toronto