Caius Boat Club (CBC; Caius pronounced keys) is the boat club for members of Gonville and Caius College, Cambridge. The club has rowed on the River Cam since 1827, and like the other college boat clubs its aim is to gain and hold the headship of the Lent Bumps and May Bumps, now held in eight-oared boats, separately for men and women.

The club had a golden era from 1998 to 2007, finding itself in the top echelons of college rowing on both the men's and women's sides. From the May Bumps 1998 until the May Bumps 2007 Caius took 19 headships, 15 of these by the men. In 2000 they became the first college to take a double headship on both the men's and women's side in the May Bumps. CBC has held the Men's Head of the River since the May Bumps 2019. During the May Bumps 2023, Caius came scintillatingly close to repeating their unique feat of holding both the men's and women's Head of the River. The women bumped up to headship on the first night, joining the men rowing over at headship station on both the second and third evenings. CBC remain the highest overall placed club on the river, with the men at headship and the women second.

From its inception in 1827 as "Caius Wherry Club" the club has been active on the river, and became properly established by the construction of its own boat house. The Club saw some prominence in its early years, holding the headship in 1840, 1841 and 1844 (when only a singular bumps order existed, and there were no women at the university), but this was followed by a long drought. In 1987 The Men regained the Mays Headship but lost it the following year.

During the May bumps of 1998, the top 3 men's crews and the top 3 women's crews all secured the awarding of Blades by bumping up on each of the 4 days with the men's 1st VIII finishing Head of the River. This 'clean sweep' of the top 6 boats being awarded their "Blades" has not happened previously, or since.

Between the Lent Bumps 2002 and May Bumps 2006, Caius men became only the second club to take 10 consecutive Headships. According to a popular myth on the River Cam, this earnt CBC the right to erect a clock tower on their boathouse, made reality when the new boathouse was finished in 2017.

The Men's crew of 2010/2011 achieved the unlikely feat of remaining unbeaten on the river Cam in eights for an entire year. This run saw them bump up 4 times to the headship of the Lent Bumps (the first time this had been achieved in either bumps since 1962, and in the Lents since before WW2) and up 2 times to the headship of the May Bumps. They also represented the Cambridge Colleges against Christ Church, Oxford in a collegiate varsity race at the Henley Boat Races, becoming the only Cambridge men's crew to be successful against their dark blue opponents that year.

Caius Boat Club has a strong tradition of developing its athletes to trial for the university boat club CUBC (and formerly CULRC and CUWBC). In 2014 there were Caians in both the men and women's Blue Boat, Goldie, the CUWBC Lightweight boat and the men's lightweight spare pair. This tradition has continued into the present day. In the Cambridge clean sweep of The Boat Race 2023, two members of the Goldie crew, one from Blondie, one from the men's spare pair, one from the women's spare pair, and one further openweight men's spare all learnt to row at CBC.

In the 25-year period between 1998 and the present day (May Bumps 2023), Caius have held the Men's Headship of the May Bumps on every occasion other than 2001 and two brief periods, between 2008 and 2010 and between 2016 and 2018. This level of consistency has not been matched by any other club in bumps history.

• Josh West, Olympic silver medalist
• Alison Mowbray, Olympic silver medalist
• Melissa Wilson, Current GB rower
• Matt Francis, Current CUBC rower

There exists a club for members who have left the college called Gonville Boat Club. Although GBC is primarily a recreational club, it occasionally enters regattas and sometimes races the current CBC 1st men's VIII. In 2008 a GBC crew took to the water with a total of 28 Cambridge headships between them.

Year	Races won
1845	Silver Wherries
1896	Visitors' Challenge Cup
1904	Thames Challenge Cup
1914	Thames Challenge Cup
1951	Wyfold Challenge Cup

• CUCBC at Cambridge University Combined Boat Club
• Caius Boat Club