Parnell moved in 1973 at the age of 10 years with his family to Alaska. After the East Anchorage High School completed in 1980, he studied from 1980 to 1984 at the Pacific Lutheran University. There he received his Bachelor. At the University of Puget Sound School of Law (now the Seattle University School of Law known), which he attended from 1984 to 1987, he received the Doctor degree JD. Subsequent Parnell began in the same year as a lawyer in Alaska and Washington to practice. He had a small law firm in Anchorage.
1992 Parnell was elected to the House of Representatives from Alaska. His father Pat had this earlier also belongs. After two terms of office to 1996 Parnell competed successfully for a seat in the Senate from Alaska. In 2006 he was elected as a Republican candidate for Lieutenant Governor of Alaska and therefore representative of Governor Sarah Palin. His predecessor and party colleague Loren Leman had no longer a candidate.
After announced on 3 July 2009 resignation of Palin Parnell took over the governorship on July 26, 2009, the office as Governor of Alaska. In November 2010 he was re-elected for a regular term of office.
Parnell is married and has two daughters. He lives with his family in Anchorage.