They will also play a four-day game against Zimbabwe A ahead of their ICC InterContinental Cup tie against Namibia.
"It's great to be playing what should be a really competitive series," said Ireland Head Coach John Bracewell. "Ireland have enjoyed some really hard tussles with Zimbabwe over the years and I expect these games will be equally as tough.
"It'll be a test for the squad playing in different conditions, and it'll also serve as good preparation for when we travel on to Windhoek for the InterContinental Cup clash with Namibia."
Ireland have played Zimbabwe only five times in ODI's since their first meeting at the 2007 World Cup ended in a dramatic tie. The African side beat Ireland convincingly in Nairobi in a one-off ODI in 2008, while they also won the only ever series between the teams, 2-1 back in 2010.
The last meeting between the teams proved one of the most exciting games of this year's World Cup as Ed Joyce hit 112 and Alex Cusack took four wickets in a nerve jangling five-run win for Ireland in Hobart.
All the games will be played in Harare, with the first ODI scheduled for Friday October 9. The second game will be on Sunday the 11th, and the third and final ODI on Tuesday the 13th. Their four-day game against Zimbabwe A starts on Saturday October 17.
Ireland will then travel to Windhoek where they will play Namibia in the latest round of the InterContinental Cup - that game starts on Saturday October 24,
