These local sides ultimately merged towards the end of the decade, and on 12 October 1889, St Ives Rugby Football Club was officially formed.

In the period prior to World War I the club supplied a number of players to the Cornwall county side, with one of these, scrum-half Thomas Wedge, capped several times by England.

[7] The re-introduction of the Cornwall Cup in the late 1960s saw St Ives continue to be one of the most dominant clubs in the county, appearing in six successive finals between 1969–74, winning three of them (including one shared).

They remained in this division for the next decade, with highlights during this period being a fourth-place finish in 1992–93, James Perkin setting a club record with an incredible 11 tries in one game against Falmouth during the 1993–94 season, and two more (losing) appearances in the Cornwall Cup final.

[11] St Ives dreadful form continued into the 1999–00 season when they finished bottom of Western Counties West with 0 wins and 18 defeats – only surviving relegation because of RFU restructuring of the league system.

They did this during 2001–02 by making an instant return to Western Counties West by finishing as runner-up in Tribute Cornwall/Devon behind champions Paignton, dead level on points but ultimately losing out due to the Devon club's superior for/against record.

[15][16] The 2004–05 season was also notable due to the coverage of the club by BBC television, following the five sets of brothers who all featured for St Ives in a league game against Crediton during the 2004–05 campaign (a record).

The next season was a mirror image of the previous, as St Ives once more finished second in the league behind Mounts Bay, and once more achieved promotion via the play-off, this time beating Swanage & Wareham 26–10 away.

[17][18] The joy of a second promotion in a row was however tinged with sadness, as first team manager Peter Burgin died following a league match against Taunton earlier in the season.

Unfortunately this yo-yo existence continued as the club had a dreadful campaign in South West 1, finishing in bottom spot with just 1 win and a draw from 22 games.

[21] The following season the club once more reached the final of the Cornwall Cup, this time losing 16–21 to Wadebridge Camels at the Recreation Ground, Camborne, in what was something of an upset.

First they stormed their way to the Tribute Western Counties West title, finishing 19 points clear of second place Devonport Services to book a return to tier 6 after an absence of six years.

[30] After maintaining a list of friendly fixtures and honouring the Cornwall Cup matches for the remainder of the season, St Ives RFC were granted a place in the lowest level of the Cornish league structure for the 2020–21.