Their management agencies on Thursday confirmed the breakup, but declined to give further details.
Lee and Suzy admitted their romantic relationship in March 2015 after they were caught dating in London by an online entertainment news outlet.
They had endured frequent breakup rumors over the years, but their relationship eventually came to an end.
Lee has been doing his mandatory military service behind a desk at the Gangnam District Office since May, while Suzy appeared in "While You Were Sleeping - 2017", a TV series that wrapped up on Thursday.
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