Quotas and tariffs on butter, anhydrous milk fat and infant formula will also be phased out over 15 years.
Fonterra Korea country manager Jason Murney said Fonterra has seen strong interest in its products off the back of the agreement, reflecting the growing demand for high quality dairy in Korea.
"The FTA will help Fonterra deepen its commercial relationships in the market over time, as our access continues to increase. We have already seen positive results, with government import statistics showing that New Zealand's share of the Korean cheddar market has grown to over 60% in 2016, up from 50% in 2015."
So far Fonterra has developed a new cheese specifically designed for pizzas.
This will help the Co-operative meet Koreans' growing taste for pizza and fusion foods, he said.