Aycox was born in Hennessey, Kingfisher County, Oklahoma. She played the piano and sang in beauty pageants as a child and does charity work. She speaks fluent German. Has a younger brother named Steve. Her mother's name is Margaret and her grandmother's name is Lillie. She has an aunt and an uncle named Louise and Steve Clements. She speaks fluent German, loves British men - according to an interview in Jack magazine -, and is known to have Native American heritage.

She is known for her roles as Syl on the series Dark Angel, a psychic cheerleader in Jeepers Creepers 2 and Stella Vessey on the dramedy Ed. She also had a stint as the unreliable sister of Detective Rush on the series Cold Case and as Pvt. Brenda "Mrs. B" Mitchell in the FX series Over There. She was the first actress to appear on CSI: Crime Scene Investigation as Captain Jim Brass' daughter, Ellie. She had a recurring role as Meg Masters in the first season of the WB (Now CW) series Supernatural. She had a role on Criminal Minds as Amber Canardo, a villainous sociopath in the episode "The Perfect Storm".

• The Line (2009) (TV) (pre-production) .... Jaimie
• Christina (2009) (post-production) .... Christina Vogel
  
• Tom Cool (2009) .... Bridget
• "CSI: Miami" .... Molly Reston (1 episode, 2008)
       - The DeLuca Motel (2008) TV episode .... Molly Reston
• Animals (2008) .... Nora
• Joy Ride: Dead Ahead (2008) (V) .... Melissa
  ... aka Joy Ride 2: Dead Ahead (USA: DVD box title)
• "Supernatural" .... Meg Masters (5 episodes, 2006-2008)
       - Are You There, God? It's Me... Dean Winchester (2008) TV episode .... Meg Masters
       - Devil's Trap (2006) TV episode .... Meg Masters
       - Salvation (2006) TV episode .... Meg Masters
       - Shadow (2006) TV episode .... Meg Masters
       - Scarecrow (2006) TV episode .... Meg Masters
• The X Files: I Want to Believe (2008) .... 2nd Victim
  ... aka The X-Files (USA: promotional abbreviation)
  ... aka The X-Files Movie (USA: promotional title)
  ... aka X-Files: Je veux y croire (Canada: French title)
• "Law & Order" .... Kate Westwood (1 episode, 2008)
  ... aka Law & Order Prime (USA: informal title)
       - Bogeyman (2008) TV episode .... Kate Westwood
• Mercenary (2008) .... Girl
• "John from Cincinnati" .... Jane (1 episode, 2007)
       - His Visit: Day Six (2007) TV episode .... Jane
• Perfect Stranger (2007) .... Grace
• "Criminal Minds" .... Amber Canardo (1 episode, 2006)
       - The Perfect Storm (2006) TV episode .... Amber Canardo
• "Over There" .... Pvt. Brenda 'Mrs. B.' Mitchell (10 episodes, 2005)
       - Follow the Money (2005) TV episode .... Pvt. Brenda 'Mrs. B.' Mitchell
       - Weapons of Mass Destruction (2005) TV episode .... Pvt. Brenda 'Mrs. B.' Mitchell
       - Spoils of War (2005) TV episode .... Pvt. Brenda 'Mrs. B.' Mitchell
       - Situation Normal (2005) TV episode .... Pvt. Brenda 'Mrs. B.' Mitchell
       - Mission Accomplished (2005) TV episode .... Pvt. Brenda 'Mrs. B.' Mitchell
        (5 more)
• "Cold Case" .... Christina Rush (10 episodes, 2004-2005)
       - Creatures of the Night (2005) TV episode .... Christina Rush
       - Kensington (2005) TV episode .... Christina Rush
       - Schadenfreude (2005) TV episode .... Christina Rush
       - Wishing (2005) TV episode .... Christina Rush
       - Revolution (2005) TV episode .... Christina Rush