The Old Chelmsfordians Association (O.C.A) was established during the Headmastership of Mr. Rogers on the 19 October 1895 when first Reunion Dinner was held at the School. The first President was Jesse Garrod, the Secretary, F.T Cramphorn and the Treasurer, J.S. Greenhow. Shortly afterwards the O.C's Football Club was formed under the captaincy of G.Lee. Red and green were the colours and the annual subscription was one shilling. The Association was active for some years organising Chess matches, Lectures, Discussions and Smoking Concerts, at the Shire Hall or Saracen's Head and sometimes at the Holborn Restaurant in London. A handbook was published yearly.

From about 1901 to 1907 the Headmaster, Mr. Rogers, fell out with the O.C.A. over our practice of inviting outside guests to the Annual Dinner. This quarrel was healed in 1907 when we again met in the School Hall. From then until 1914 the O.C.A. prospered, but the outbreak of war led to a complete of its activities and indeed its existence.

After the war steps were taken to revive the Association. In February 1920 a preliminary meeting was held in November 1921 a General Meeting decided to restart the O.C.A. The Headmaster, T.Hay, was elected President, with R.A. Barker as Secretary and Treasurer. About five years later there was again a period of difficulty but the Presidency of S.C. Taylor (1928-30) and the Secretaryship of L.J. Dixon (1927-28) gave the Association a new lease of life. The Annual Dinner was revived in 1925 and an Annual Dance was held from 1930 onwards. An O.C. tie and blazer were designed and a life membership subscription initiated. The Association presented to the School a pair of ornamental gates as a Coronation gift. The new found energy made it possible to keep the O.C.A. alive throughout the 1939-1945 war.

As members returned from the Forces we took another leap forward in the expansion of the Sports and Social sections and in the launching of a War Memorial Fund. This led to the acquisition of land at Lawford Lane for our Sports Field and Headquarters which was officially opened in July 1951.

The Association has continued to grow in strength since that time and the facilities at the Lane have also been constantly improved. The original 'Green Hut' was replaced by a converted ‘Chicken Shed’ and continued in use for storage until it was sadly burned to the ground. However the ‘Chicken Shed’ remains today although dressed differently as the Members Lounge. In 1973 what is still referred to as the 'New Hall' was built and the granting of a special licence to hold external functions meant that it has become not only a home for many of our social occasions but also a considerable fundraiser. In 1989 a £100,000 appeal was launched to again upgrade the facility in readiness for the 1990s.

It was always anticipated that the early years of the new millennium would be a difficult period and see a new challenge being faced by the Association. With an ever increasing number of the KEGs pupils living further from the School, nearly all of whom would inevitably leave the area for universities throughout the country and with interests in so much more than just football and cricket, the need to maintain our membership and sporting heritage would be paramount to enable us to maintain the quantity and quality of the sporting activity on offer within the Club. With the traditional enthusiasm, hard work and energy of our members and the support of the then new Headmaster, Dr. Mike Walker, the already strong link between the School and Association continued to flourish and the challenge was met.

The generous bequest to the Association by John Allen early in the century led to much discussion and planning as to how to spend this for the benefit of all before a final decision was taken to completely rebuild the members’ bar area to provide a greater social space and open this up to the field area to bring both the sporting and social aspects of the Club together. The new buildings were officially opened in February 2008 and have been the catalyst for an upturn in social functions with the rebirth of an active social committee whilst sport has continued to prosper with additional teams being introduced by all the sections.

Membership is worldwide and well in excess of 1000 with current corporate members having enjoyed schooling at KEGs from the 1920s through to the present day and with many of today’s boys already enjoying their sport with us whilst our doors have been opened to many non KEGs pupils to ensure the full use of our facilities and to whom a warm welcome has been extended. Football, Cricket, Tennis, Table Tennis, Summer Hockey, Golf Outings, Indoor Bowls and Snookerare all part of the Association's sporting profile and with Tom Carter, appointed head teacher in October 2014, keen to help find ways to further cement the already strong bond between the School and Association, we can all feel positive about the future.