"I resigned from the BSP today. I have joined the BJP in the presence of party state unit president Krishna Pal Gujjar at a programme in Faridabad," Sharma told PTI.
"I categorically confirm that I will not contest the assembly elections in the state. But I will fully participate in the election campaign of BJP," he added.
Sharma had contested from the Faridabad Lok Sabha constituency on a BSP ticket earlier this year. He said accepting a BJP ticket at this juncture would deprive a committed worker from the opportunity to contest.
Sharma was critical of the BSP, saying the party was "engaged in selling ticket" to those wishing to contest. "The so-called social engineering of the BSP has failed. It has become shoshan (exploitation) engineering. The Brahmins have especially suffered under BSP," he alleged.
The ace cricketer was the first to get a hat-trick in one-day cricket but had drawn a lot of ire after he was hit for a six on the last ball of a final in 1986 at Sharjah by Pakistan batsman Javed Miandad which cost India the match.
Sharma said he had a clean record as a cricketer and could not bear to be with a "corrupt" BSP. He earlier held a meeting with BJP president Rajnath Singh before taking the plunge.