The France international right-back is set to join the Magpies when the transfer window re-opens next week, subject to him passing a medical and agreeing personal terms.
The 27-year-old has been a long-term target for Newcastle, who tried and failed to sign him last summer.
Real Madrid and Inter Milan were also keen on Debuchy earlier this year - but now he is set to become the latest French recruit for manager Alan Pardew.
Newcastle's Yohan Cabaye, who also arrived from Lille, is close-friends with Debuchy and is believed to have been a major factor in persuading him to move to Tyneside.
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