The 56-year-old actress will play Maya Lewis in a recurring role on ABC's political drama. Alexander will make her first appearance on the show Thursday in a series of flashbacks.
Last week's Scandal episode revealed that President Fitzgerald Grant (Tony Goldwyn) was responsible for shooting down a civilian airliner with more than 300 passengers on board -- one of which was the mother of Kerry Washington's character Olivia Pope.
Scott Foley, who plays Jake Ballard, a naval officer hired by president Grant to spy on Pope, said the show would flash back to when Pope was a little girl. Goldwyn added that Alexander's character would be a "major issue" in the show's plot.
"You can only imagine what that would be like to find out that your mother did not die in the way that you thought she died, in terms of it being a willful act. It's surreal for Olivia," Goldwyn told THR.
"The audience can imagine what that must be like to find out that your mother was murdered along with hundreds of other people. So the fact that her father was behind it is incomprehensible. It's going to really complicate [Olivia and Rowan's relationship] because Rowan remains a very dangerous person. It's not like everyone can just expose him or take him out. It becomes a very volatile and dangerous situation. You can imagine how devastating it is for Olivia."
Alexander is best known for her roles in CSI: Miami, The Corner and ER.
Scandal airs Thursdays at 10 p.m. on ABC.