"I have so many fond memories of playing in and visiting South Africa, and when this opportunity came about, I couldn't say no because of how special it would be to come back to playing competitive cricket and win this incredible competition with the Royals," said Karthik, who has played 180 matches for India across all three formats.
His last competitive T20 outing was for RCB in the IPL 2024, for whom he made 326 runs in 14 matches at a strike-rate of 187.36.
Karthik's last match in India colours was against Bangladesh during the T20 World Cup in Australia in 2022.
"I am delighted to be joining the Paarl Royals team which oozes a lot of experience, quality and potential. I am certainly looking forward to joining the group and contributing to what should be an exciting season," Karthik, who was roped in as the league ambassador a day earlier, said.
Royals' Director of Cricket, Kumar Sangakkara, hoped to tap in the extensive T20 experience of Karthik.
"Dinesh has served as one of the modern-day greats for India in white-ball cricket, and his wealth of experience will contribute to the making of our side.
"He has always proved to be a great asset for the teams he's represented across leagues for the way he approaches the game and the impact he can make," said Sangakkara.
At the Royals, Karthik will join other international stars like skipper