KELT-2Ab is an extrasolar planet that orbits the star KELT-2A approximately 440 light-years away in the constellation of Auriga.

[1] It was discovered by the KELT-North survey via the transit method - so both its mass and radius are known quite precisely - in a paper led by Thomas Beatty.

As of its discovery KELT-2Ab is the fifth-brightest transiting Hot Jupiter known that has a well constrained mass.

This makes the KELT-2A system a promising target for future space- and ground-based follow-up observations to learn about the planet's atmosphere.

[3] The water vapour was detected in planetary atmosphere in 2018.