Irwin grew up in Meadville, Pennsylvania with her mother Melinda, father Jim and brother J.R. Irwin. She graduated from University of Pittsburgh in 2002, majoring in exercise physiology. While in college she was a member of Delta Zeta sorority and Pitt dance team.
In 2001 she won the Miss Crawford County title and competed in the Miss Pennsylvania pageant and competed again as Miss Steel Valley in 2002. In 2003 Irwin was crowned Miss Greater Juanita Valley but was unable to participate at Miss Pennsylvania because she was appearing on her first season of Big Brother at the time. During the 2001 pageant, Irwin competed against Erika Shay, who would also appear on The Amazing Race 5.
Big Brother 4
During the summer of 2003, Irwin participated in the reality TV series Big Brother 4 which aired on CBS. She finished runner-up to Jun Song after eighty-two days in the house, for which she received $50,000. She was on the losing end of a landslide 6-1 final vote in Jun's favor.
Amazing Race 5
In 2004 she participated in The Amazing Race 5 with her boyfriend, Donny Patrick, a football player at Bloomsburg University. The two had been together since prior to Irwin's participation on Big Brother. The shows producer Bertram van Munster was initially upset at their casting for the season. After finishing the first episode in first place, Irwin and Patrick were eliminated the very next episode, finishing in 10th place. Irwin refused to appear next to Patrick for the traditional assembly of all the non-Final 3 teams alongside the $1 million final Pit Stop, leading CBS to use CGI to insert a stock image of Irwin next to the actually-there Patrick.
Big Brother: All Stars
In 2006, Irwin returned to the Big Brother house to take part in the All Stars edition. She was the first to be eliminated by a vote of 8-2 on July 13, 2006. She expressed happiness over Erika Landin's lopsided Final 2 defeat, gloating that Mike Malin had "played" her and laughing that Erika would need a lot of therapy afterwards. Coincidentally or not, Irwin has never had any appearance related to BB since then.
She also appeared on a very small reality series, Too Tall For Small.
- Owen, Rob (2003-07-04). "'Big Brother' star hails from Meadville". Pittsburgh Post-Gazette. Retrieved 2007-02-24.
- Owen, Rob (2003-09-26). "Alison has no 'Big Brother' regrets". Pittsburgh Post-Gazette. Retrieved 2007-02-24.
- "Miss Pennsylvania Contestants through the years". Miss Pennsylvania organization. Retrieved 2007-02-18.
- Levin, Gary (2005-02-09). "Freddy, Kendra engaged to the end". USA Today. Retrieved 2007-02-24.
- "Anderson: Ex-Pitt WR deals with reality". Pittsburgh Post-Gazette. 2006-06-08. Retrieved 2007-02-24.