Narsingh had tested positive for a banned substance ahead of the Rio Olympics. But he was cleared by the National Anti Doping Agency (NADA) which allowed him to travel to Rio.
But the WADA exercised its right to appeal against the NADA's verdict to the CAS which cleared the Mumbai grappler on Thursday.
"Narsingh Yadav has been cleared by the CAS to participate in the Rio Olympics," Narsingh's lawyer told reporters after the CAS ruling here.
Narsingh will start his Olympic campaign against Zelimkhan Khadjiev of France in the qualification round of the men's 74 kg Freestyle category on Friday.
The 26-year-old grappler also underwent his weigh-in on Thursday, which ensured his participation for Friday.
The CAS ruling brings an end to a long ordeal for Narsingh.
He was preferred over double Olympic medallist Sushil Kumar to take part in the Olympics by the Wrestling Federation of India (WFI) that led to a major legal battle between the two wrestlers.
Narsingh, who bagged the quota with a bronze medal finish in last year's World Championships then ran into trouble over alleged doping offences. He first returned positive for a banned steroid following a dope test on June 25 by NADA, before being cleared on August 1.
The Wrestling Federation of India (WFI) also communicated to the world's apex wrestling body, the United World Wrestling (UWW) that NADA has cleared Narsingh of all the doping-related charges and the 26-year-old would be re-included in the team for the 74kg competition.
The UWW gave the green light to Narsingh for participation on August 3. However, Narsingh's route had to clear the final WADA hurdle to compete, which reviewed the NADA panel verdict and challenged it at CAS for further deliberation.
Narsingh had claimed of a conspiracy to frame him and had filed a police report in this regard, although he refrained from naming anyone.
WFI chief Brij Bhushan Sharan Singh had backed Narsingh's claims and had asserted that a conspiracy was hatched to stop the wrestler from participating in the Olympics and this needs to be exposed in order to secure future generations of sportspersons.
