Ruislip-Northwood Swimming Club was formed in the late fifties/early sixties and over the years rapidly grew into a very large club, incorporating all sections of water sports. Competitive swimming, learn-to-swim, masters, diving, sub aqua, life saving, synchro, snorkel and social swimming were all part of the same club with a member from each section sitting on an executive committee. Different sections fluctuated in their membership numbers although the competitive section remained the largest and most predominant one throughout. This continued until, in 1987, it was felt that the representation on the Ruislip-Northwood Swimming Club committee did not reflect the level of membership and revenue of the competitive section.

In 1987 the competitive swimming section along with the learn-to-swim revised their own constitution and finances and independently registering with the Southern Counties ASA but still remained affiliated to Ruislip-Northwood Swimming Club. On having its own constitution and being registered independently with the ASA the competitive swimming section could not continue with the same name as the main club. It was therefore decided to call ourselves Ruislip-Northwood Swim Squad.
In 2006 RNSS agreed to host the Hillingdon Borough Elite swimmers after the Hillingdon Borough Swimming Club closed. Hillingdon Borough Elite Swimming Team (H.B.E.S.T.) accordingly became a squad within RNSS.
In December 2007 the top level club name was changed to Hillingdon Swimming Club by agreement of its members.
Hillingdon Swimming Club currently has 2 houses, the parent house Ruislip-Northwood Swim Squad as well as H.B.E.S.T. house which caters for he Hillingdon Borough Elite Swimming Team.