The Cavalier Fanciers of Southern Ontario Club was formed in 1988, when a group of active, local breeders decided that a regional club would add to their knowledge and enjoyment of the breed. As well, the social interaction amongst its members would encourage others interested in cavaliers to join, and expand the diversity of the club. The first meeting took place in February 1988 at the home of George and Jane Dewar in St. Catharines. From the beginning, it was decided that an applicant must first be a member of the Cavalier King Charles Spaniel Club of Canada before becoming eligible to join CFSO. This was an indication to the National Club that CFSO wished to work in co-operation with the CKCSCC, and not in competition with it. In September 1989, CFSO received official recognition from the Canadian Kennel Club. 

As membership grew, The Club decided to hold a specialty show each year to showcase our breed in this area. The first step was to organize a sanctioned match which was held on May 27, 1989. The first CFSO regional Specialty show was held in 1991 on the grounds of Brinklow Hill, and that yearly show on the last Sunday in June continues to this day. Canadian judges and breeder judges from overseas are chosen alternately for the show. 

Since education of breeders and the public is one of the mandates of the Club, CFSO participates in three main events in this regard. An eye clinic, open to all breeds, has been held each autumn since 1988. In recent years this has expanded to include a heart clinic. The second event is participation in the Sportsmen's Show in Toronto each spring where club members staff a booth and introduce their cavaliers to the public, answering questions and handing out educational material on the breed. In 1996 the club devised and produced a Puppy Buyer's Guide, and this has been so helpful and successful that other clubs have asked permission to reproduce it for the information of pet buyers in their areas. It has been updated several times and continues to be a help to cavalier clubs both here and in the United States. A third yearly event was established in 2002 and is held in September. The Cavalier Pet Picnic is open to all cavaliers and their human families. The intent was to provide a day of fun and enjoyment without the kind of serious competition found at dog shows. This event continues at Brinklow Hill to this day. There are games for dogs and people, a terrific potluck lunch and a Chinese auction to help defray the costs of the event. Thanks to the success of the Chinese Auction, the Club has been able to make donations to the National Club's Health & Education committee, Rescue and the Yearbook. Other educational events are held as well, ranging from weekend seminars to one-day events, to shorter information presentations at meetings. 

From September to May each year, CFSO hosts a series of show handling classes helping both the novice and experienced handlers improve their skills, and their dogs learn to enjoy the show ring. The club has grown from strength to strength in its life. Membership has grown from the beginning of 17 in 1988 to approximately 100 in 2011. One of the most important elements in keeping CFSO strong has been the co-operative and happy atmosphere that pervades its activities. Long may it continue. In 2008, CFSO celebrated its 20th year as a club. On June 27th, 2010 we celebrated our 20th Specialty Show.