MOA-2007-BLG-400Lb is an extrasolar planet located approximately 20000 light-years away in the constellation of Sagittarius, orbiting the star MOA-2007-BLG-400L. This planet was detected on September 18, 2008 by the gravitational microlensing by Dong. It has mass between 50% and 130% of Jupiter and orbits between 0.6 and 1.1 AU.

• Dong, Subo; et al. (2009). "Microlensing Event MOA-2007-BLG-400: Exhuming the Buried Signature of a Cool, Jovian-Mass Planet" (abstract). The Astrophysical Journal. 698 (2): 1826–1837. arXiv:0809.2997. Bibcode:2009ApJ...698.1826D. doi:10.1088/0004-637X/698/2/1826. S2CID 16658501.web preprint

• "MOA-2007-BLG-400-L". Exoplanets. Archived from the original on 2009-11-25. Retrieved 2008-10-11.