House Democratic leader Nancy Pelosi will appear on the series finale of NBC’s ‘‘30 Rock.’’ Pelosi’s office confirmed Friday the California congresswoman will appear but did not reveal any other details. The final episode of Tina Fey’s comedy is scheduled to air Jan. 31, ending seven seasons for the Emmy Award-winning show. Other politicians who have appeared on the show include former Vice President Al Gore, former Secretary of State Condoleeza Rice, and New York Mayor Michael Bloomberg.