From A Wiki of Ice and Fire
An assassin is one who commits a targeted murder or assassination, mostly for political reasons. They may act alone or in organised groups, or in Melisandre's case, be created by magic.
- A Catspaw, hired to murder Bran Stark while he lay in a coma.
- The Alchemist.
- The Faceless Men, a religious society of assassins based in Braavos.
- The Sorrowful Men, an ancient guild of assassins from Qarth.
- A shadow assassin, a form of magic used by the shadowbinder Melisandre of Asshai.
- Jaqen H'ghar
- Arya Stark
- Blood and Cheese, who were hired by Daemon Targaryen to kill the young son of Aegon II, Prince Jaehaerys.
- Tessario the Tiger, a sellsword in the service of Unwin Peake, who may have murdered young Queen Jaehaera Targaryen.