SI Founder Manila is part of Soroptimist International, an international volunteer service organization for business and professional women who work to improve the lives of women and girls, in local communities and throughtout the world.

Soroptimist International Founder Manila was founded by civic leader Mariquita S. Castelo on May 5, 1966 . It was chartered as the Soroptimist Club of Greater Manila later to be known as Soroptimist International Founder Manila (SIFM). Distinguished women professionals and entrepreneurs were inducted in the music room of Malacanang Palace with the First Lady Imelda R.Marcos as guest of honor and Ms. Pluma B. Batten, Director of the Soroptimist Federation of the Americas presenting the charter.

The first officers of the Club were the following :

Mariquita S. Castelo, President
Charito Planas , 1st Vice-President
Lourdes E. Guillermo, 2nd Vice-President
Lilia R. Gonzales, Secretary
Leonor E. Pablo, Treasurer
Ileana Maramag and Naomi Osborne, Board Members

Other chartered members were:
Diwata Aldaba-Baluyot
Josefa Castelo
Lutgarda Castelo
Ester Garrovillas
Carmen Kalaw
Mercedes Lising
Angelica Mendoza
Eva Ponce Panajon
Soledad Teodoro
Lucrecia Urtula

On May 5, 2006, SI Founder Manila will be celebrating its 40th year anniversary. Through the years, SIFM has actively pursued the Soroptimist ideals through its service programs and community projects focused directly on the welfare and plight of women in the Philippines , particularly the indigents and the marginalized.

The Clubs' centerpiece program is its Adopt-A-Barangay covering the SI Six Program Areas: