Ninth Circuit Judgeship and Reorganization Act of 2005 - Amends the Federal judicial code to divide the Ninth Judicial Circuit into the Ninth Circuit (to be composed of California, Guam, Hawaii, and the Northern Mariana Islands), and the Twelfth Circuit (to be composed of Alaska, Arizona, Idaho, Montana, Nevada, Oregon, and Washington.

Requires the President to appoint five additional circuit judges for the new Ninth Circuit and two temporary judges for the former Ninth Circuit.

Specifies the locations where new circuits are to hold regular sessions. Locates the offices of the new Twelfth Circuit in Phoenix, Arizona.

Assigns active circuit judges of the former Ninth Circuit to the new circuits. Allows senior circuit judges of the former Ninth Circuit to elect assignment.

Specifies the disposition of cases pending in the former Ninth Circuit before the effective date of this Act as follows: (1) proceedings in matters that have been submitted for decision shall continue without regard to this Act; (2) matters not yet submitted for decision must be transferred to the court to which they would have been submitted under this Act; and (3) petitions for rehearing en banc that are pending shall be considered by the court to which they would have been submitted had this Act been in full force and effect at the time that the appeal or other proceeding was filed.

Authorizes the temporary assignment of circuit and district judges of the former Ninth Circuit among the new circuits.

Directs that the former Ninth Circuit shall cease to exist for administrative purposes two years after enactment of this Act.