Kankiwala has worked on global brands including Unilever and PepsiCo and is a former president of Burger King International.
The company will look at extending its range of 50 products, which are created under the ethos of 'real food for babies, not just babyfood', and is considering possible international expansion, Kankiwala said.
"Plum is a fantastic brand with significant growth potential. For the long term we will be looking at whether we can grow outside the UK. With my international background I can help," he said. "I will lead the board and make sure the strategy is clear."
Kankiwala's appointment follows the purchase of Plum by Darwin Private Equity in May and Paul Kaye joining as CEO.
As group CEO and now group executive chairman of Mayborn Group, Kankiwala helped create the sixth largest and fastest-growing baby accessories company, with global brands Tommee Tippee and Sangenic. He also led the public-to-private acquisition of the group via a £137m deal with 3i and Barclays' investors/debt partners.
"Nish brings invaluable experience and an exceptional track record in the food and baby arena, said Kaye. "He will play a key role in taking us to the next level."