In the fictional setting of Robotech, the SDF-2 Megalord is the second Super Dimensional flagship of the United Earth Forces that was abruptly introduced offscreen in the dialogue of the 36th and final episode of The Macross Saga segment.
Limited only to existing footage of the SDF-1, a new SDF-2 is never seen and presumed destroyed with the SDF-1 sometime during the Khyron's attack of New Macross City in 2014. Its surprise non-appearance and the ambiguity of its outcome has been an endless source of confusion and debate among Robotech fans.
The Robotech comic adaptation by Comico depicts the SDF-2 as sitting back to back with SDF-1 in Lake Gloval. This was expanded upon in the Robotech novels by Jack McKinney. It is similar in appearance to SDF-1 and seems to have been intentionally built in the original ship's post-modular transformation mode. This is unusual given that the purpose for transformation in the original was due to circumstance, not design. However, the novel explains this was to facilitate the transfer of the engines from the SDF-1 to the SDF-2, although this never actually happens. Since the ship is visualized in the comics as being similar to the SDF-1 (though armed with ARMD class carriers), it is generally assumed to be a second Macross-class battlefortress.
According to the Robotech novels, some of its remains are buried at the three mounds that play a key part of the Second Robotech War. The rest of its components and materials were scavenged for the construction of the new SDF-3.