Prime Minister Stephen Harper says Canada is sending 500 people to monitor the election proceedings.
Of the total, 338 will be with Canada's independent election observation mission.
Another 162 will be part of observation missions run by the Organization for Security and Co-operation in Europe.
Andreychuk led Canada's delegations for Ukraine's 2010 and 2012 elections.
Harris served as Progressive Conservative premier of Ontario from 1995 to 2002.