Kim opted to step down from The Korea Fund, a subsidiary of Allianz Global Investors, last month.
Leung, who formerly worked for Allianz Global Investors between 2001 and 2006, joins as lead portfolio manager on the Allianz Korea Fund.
During his time away from Allianz, Leung had focused on long/short equity investments in the Korean and Hong Kong/China markets.
It has not been revealed whether Kim, who had been lead manager on the Dublin-domiciled fund since December 2008, intends to stay within the fund management industry.
Meanwhile, Raymond Chan, chief investment officer for Allianz Global Investors, Asia Pacific, will continue to serve as a co-manager on the Ucits-compliant fund.
Over the three years to the end of March 2014, the Allianz Korea Fund lost 18.8%. This is while its Citywire benchmark, the KOSPI Composite CR, fell 5.75% over the same period.