I think a little younger Joaquin Phoenix would be perfect.
Commodus in Gladiator was basicaly an ancient Roman Palpatine.
From killing their fathers to inherit their power (palpatine in a novel), to taking control of the militaries, trying to disolve the senate to assume total control, etc...
Also much like Ian McDiarmid, Phoenix was great in his contrast from being the noble leader to the public to the evil sociopath behind closed doors.
Originally posted by BruceSkywalker
lets gender swap and go with some unknown actress
Can just add an A at the end. Sheeva Palpatine. 😄
In all seriousness, there have been a couple of good suggestions here. Tom Hiddleston and Dan Stevens could both potentially kill it IMO. Stevens really impressed me with his acting chops on Legion.