Kohli, who has been named India skipper for the fourth and final Test against Australia, starting on January 6 in Sydney, tweeted a selfie with thumbs up sign about his new achievement on Twitter.
The right-hander from Delhi thanked all his followers for this. He is now the most followed sportsperson in the country. Batting legend Sachin Tendulkar is second.
"Wow that was a quick ride to 5 million! Great start for the new year. Thank you all for making it possible :)," Kohli tweeted.
In October last year, he had crossed 4-million mark. He had posted a selfie then about it. Now in 14 months from then, he has added 1 million more followers.
MS Dhoni retired from Test cricket on December 30 and Kohli was named as his replacement to take charge of the team.
India have lost the four-match Test series 0-2 to Australia and they will be hoping to pull one back in the final Test in Sydney under Kohli's leadership.