German media reports Leverkusen do not have an option to buy at the end of the loan period.
Mukiele arrives as a replacement for centre-back Odilon Kossounou, who has moved to Europa League winners Atalanta.
The defender is looking for more playing time, having only started nine Ligue 1 matches in the previous season for the French champions.
The 26-year-old France defender has experience in the Bundesliga, having spent four years at RB Leipzig before his move to PSG in 2022.
“For me it’s an incredible thing to come back to Germany — and to join the German champions,” Mukiele said in a statement.
Mukiele played exactly 100 Bundesliga games for Leipzig, scoring eight goals, and could face his former side when the two clash in Leverkusen on Saturday.
Germany’s transfer window closes at 8pm on Friday.
© Agence France-Presse
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