Darren Lapthorne (born 4 March 1983) is an Australian former professional racing cyclist.^[1]

Born in Melbourne, Lapthorne began his career in 2006 with the Australian Professional Team Drapac–Porsche. In his first year, he won the road race of the Teams Road Championships. He also finished third in one stage of the Herald Sun Tour. In January 2007 he achieved his greatest success by winning the Australian National Road Race Championships. He rode for the German Team Sparkasse in 2008 and for British team Rapha Condor in 2009.

He retired from professional racing in 2016.^[2]

In December 2008, Lapthorne returned to competition after 2 months out^[3] following the much-publicised 18 September 2008 disappearance and death of his younger sister, Britt (born 1987), while she was backpacking in Dubrovnik, Croatia.^[4][5] During this time, Lapthorne was heavily involved in the early informal efforts to identify her whereabouts,^[6][7] and for helping to expose the lack of attention given to the case by local police. In late 2008, he assisted in the repatriation of her remains to Australia^[8] and also attended the subsequent state coroner's hearing in 2015.^[9]