The Lent Bumps 2005 were a series of rowing races held at Cambridge University from Tuesday 1 March to Saturday 5 March 2005. The event was run as a bumps race and was one of the series of Lent Bumps which have been held annually in late February or early March since 1887. See Lent Bumps for the format of the races. In 2005, a total of 121 crews took part (69 men's crews and 52 women's crews), with nearly 1100 participants.
Caius men rowed-over in 1st position, retaining the headship for the 4th consecutive year.
Downing women rowed-over in 1st position for the 2nd year in a row, their first successful defence over the headship.
The highest men's 2nd VIII for the 6th consecutive year was Caius II, despite losing their place in the 1st division to King's.