Dr. Moira Kinross MacTaggert is a fictional character in the X-Men stories in Marvel Comics' universe.

The character is one of the world's leading authorities on genetic mutation. She is Professor Charles Xavier's colleague, confidante, and was also once his fiancée. Born Moira Kinross to Scottish parents, she met and fell in love with Xavier while they were attending graduate school at Oxford University. She ended their engagement when for reasons unknown she married her old flame, the late politician Joseph MacTaggert. Their marriage was an unhappy one (and was never legally dissolved). Before Moira left Joe, he raped her. The product of that rape was a son named Kevin, a mutant who would later be called Proteus . She also legally adopted the orphaned mutant Rahne Sinclair (Wolfsbane), who considers her a second mother.

Her research station on Muir Island, Scotland, is off the northern coast of Cape Wrath. This facility has, among other facilities, a hospital, a large computer center, a large research center, and confinment areas for mutants considered to be dangerous. For a time it also served as HQ to the mutant team Excalibur.

She redirected her energies into finding a cure for the Legacy virus, and was the only non-mutant ever to have contracted the disease. She was ultimately killed by an explosion caused by Mystique, but not before finding a cure and giving it to Xavier.