South Harrow Baptist Church was opened in 1935 and although a pipe organ was planned, this project was delayed as a result of the second world war and so a reed organ was used until the present instrument was built by the John Compton Organ Ltd and opened with a recital by Dr George Thalben Ball on 30th April 1949.

This is believed to be Comptons first new pipe organ installation in the post war years. The organ is built using the extension principal with the pipework, including the Compton patent 32ft polyphonic bass, contained in a fully enclosed chamber speaking through ornamental grilles.

In 1977 a Vox Angelica rank was added by local organ builder Keith Bance. A Rohr Flute rank has also been added. In 2005 the organ was given an overhaul and new solid state action fitted as well as a complete rewire.

The specification reads:

Sub Bass 32'
Sub Bass 16'
Octave 8'
Flute 8'
Flute 4'
Trombone 16'
Trumpet 8'
Great to Pedal
Swell to Pedal

Bourdon 16'
Open Diapason 8'
Rohr Flute 8'
Salicional 8'
Octave 4'
Stopped Flute 4'
Salicet 4'
Twelfth 2.2/3'
Fifteenth 2'
Trumpet 8'

Contra Salicional 16'
Hohl Flute 8'
Salicional 8'
Vox Angelica 8'
Flute 4'
Salicet 4'
Nazard 2.2/3'
Piccolo 2'
Tierce 1.3/5'
Cymbale III
Trombone 16'
Trumpet 8'
Clarion 4'

4 double touch thumb pistons to Great and Pedal
4 double touch thumb pistons to Swell and Pedal
4 toe pistons to Pedal
1 canceller thumb piston - Great to Pedal
1 canceller thumb piston - Swell to Pedal
1 balanced expression pedal - organ
1 balanced expression pedal - crescendo
Double touch canceller to each department