Krishnakumar Dinesh Karthik (born 1 June 1985 in Madras, Tamil Nadu, India) is a wicketkeeper-batsman who has made his debut for the Indian cricket team in 2004 and has been a regular member of the team for varying periods since then, including a stint in 2007 as a specialist opening batsman and non-wicket-keeper. Karthik was a batsman in his junior career, but turned to wicket-keeping in order to improve his future prospects. Throughout his career, Karthik has been criticised for unreliable glovework symptomatic of a non-specialist wicket-keeper.
Rising through the junior ranks, Karthik made his first-class debut in late-2002 for Tamil Nadu as a 17-year-old, and was dropped in his first season despite his healthy run-scoring because of his problematic glovework. He fought his way back into the team and after playing for India at the 2004 Under-19 World Cup, made his ODI and Test cricket debut in late-2004. This came after India had struggled to find a reliable gloveman in the past few years. Karthik was the regular wicket-keeper in Tests, making rare appearances in ODIs. During this period, Karthik struggled and averaged less than 20 with the bat, and he was replaced as Test wicketkeeper by Mahendra Singh Dhoni, who had been prolific and destructive with the bat in ODIs, in late-2005. After donning the mantle of an opener for Tamil Nadu and raising himself to the standard of a specialist batsman at domestic level, he was recalled to the national squad as a batsman in late-2006 after injuries and form slumps hit other batsmen, playing occasional matches in both forms of cricket on the tour to South Africa, and scoring a half-century in a Test as an opener. Following India's elimination from the first round of the 2007 Cricket World Cup, the selectors made multiple changes, and Karthik became a non-wicket-keeping opening batsman in the Test team and regularly played ODIs, batting in the middle order. He made his maiden Test century against Bangladesh and then was India's leading scorer in the Test tour of England, helping India to win their first series in England in 21 years. However, Karthik suffered a form slump in late-2007 and was dropped from the Test team, and since then has only made sporadic international appearances, although he continues to score heavily in domestic cricket. These have come in occasional appearances as a specialist batsman when other players were rested or injured, or as a wicket-keeper when Dhoni was sidelined. Karthik's glovework for India continues to be criticised.