Although Brooklyn Monthly Meeting officially came into being only in January of 1975, its history extends back nearly 160 years.

In 1835, the New York Monthly Meeting (Hicksite) allowed a Meeting for Worship in Brooklyn under its care. By 1837, the worship group had grown to the point where it sought and granted recognition as Brooklyn Preparative Meeting (Hicksite) of the New York Monthly Meeting.

The next year, Brooklyn Hicksite Friends had built themselves a new Meetinghouse at the corner of Henry and Clark streets. 20 years later, in 1857, a new Meetinghouse was ready for occupancy at the corner of Schermerhorn Street and the street now known as Boerum Place. This Meetinghouse still stands and remains the home of the Brooklyn Monthly Meeting.

While Hicksite Friends were establishing themselves in Brooklyn, Orthodox Friends were similarly engaged. In 1860, an allowed Meeting for Worship in the Orthodox manner began in rented space at a well-known Brooklyn school, Packer Collegiate Institute. By 1868, this Meeting had also built its own Meetinghouse at the corner of Washington and Lafayette Avenues. In 1869, Orthodox Friends in Brooklyn were established as a Monthly Meeting. It was at that time called Brooklyn Congregational Meeting.

The two separate Brooklyn Meetings continued for nearly a century. By the 1950s, the issues that had originally led Friends to split began to seem less important than the need to heal old wounds and end the schism. Perhaps this process was aided in Brooklyn by a steady decline in attendance at the Orthodox Meeting – which by this time was called Brooklyn Friends Church (popularly known as Lafayette Avenue Meeting).

In 1959, Brooklyn Friends Church, citing drastic changes in population patterns, formally laid itself down. Its members were offered the option of either discontinuing their membership in the Society of Friends or of transferring to other Meetings. The largest number chose to affiliate with Brooklyn Preparative Meeting, which, in turn, agreed to accept into membership any Lafayette Avenue Friends who wanted to join. The former Orthodox Meetinghouse was sold in the early 1960s to a church of another denomination. It still stands and is in regular use.

Within the newly enlarged Brooklyn Preparative Meeting, Friends who formerly considered themselves Hicksite and Orthodox found they could worship, work, and socialize together without compromising their individual spiritual convictions. A decade and a half following the Brooklyn merger, the New York Monthly Meeting reconstituted itself as the New York Quarterly Meeting. Its constituent preparative Meetings, including Brooklyn Monthly Meeting, at last became Monthly Meetings.