* 1999: Won, "TV - Choice Actress" — Buffy the Vampire Slayer
* 2000: Won, "TV - Choice Actress" — Buffy the Vampire Slayer
* 2001: Nominated, "TV - Choice Actress" — Buffy the Vampire Slayer
* 2001: Won, Extraordinary Achievement Award
* 2002: Won, "TV - Choice Actress, Drama" — Buffy the Vampire Slayer
* 2002: Won, "Film - Choice Actress, Comedy" — Scooby-Doo
* 2002: Nominated, "Film - Choice Chemistry (with Freddie Prinze Jr.)" — Scooby-Doo
* 2003: Won, "TV - Choice Actress, Drama/Action" — Buffy the Vampire Slayer
* 2005: Nominated, "Choice Movie Actress - Action/Adventure/Thriller" — The Grudge

MTV Movie Awards

* 1998: Nominated, "Best Breakthrough Performance" - I Know What You Did Last Summer
* 2000: Nominated, "Best Villain" — Cruel Intentions
* 2000: Won, "Best Female Performance" — Cruel Intentions
* 2000: Won, "Best Kiss", Shared with Selma Blair — Cruel Intentions
* 2005: Nominated, "Best Frightened Performance" - The Grudge

Blockbuster Entertainment Awards

* 1998: Won "Favorite Supporting Actress - Horror" - I Know What You Did Last Summer

Golden Globe Awards

* 2001: Nominated, "Best Performance by an Actress in a TV Series - Drama" — Buffy the Vampire Slayer

Saturn Awards

* 1998: Nominated, "Saturn Award for Best Actress on Television" — Buffy the Vampire Slayer
* 1999: Won, "Saturn Award for Best Actress on Television" — Buffy the Vampire Slayer
* 2000: Nominated, "Saturn Award for Best Actress on Television" — Buffy the Vampire Slayer
* 2001: Nominated, "Saturn Award for Best Actress on Television" — Buffy the Vampire Slayer
* 2002: Nominated, "Saturn Award for Best Actress on Television" — Buffy the Vampire Slayer
* 2003: Nominated, "Saturn Award for Best Actress on Television" — Buffy the Vampire Slayer
* 2004: Nominated, "Saturn Award for Best Actress on Television" — Buffy the Vampire Slayer

Golden Satellite Awards

* 2002: Won, "Outstanding TV Ensemble" — Buffy the Vampire Slayer
* 2003: Nominated, "Best Performance by an Actress in a Series - Drama" — Buffy the Vampire Slayer

Daytime Emmy Awards

* 1994: Nominated, "Outstanding Younger Leading Actress in a Drama Series" — All My Children
* 1995: Won, "Outstanding Younger Leading Actress in a Drama Series" — All My Children

Young Hollywood Awards

* 2002: Won, "Hottest, Coolest Young Veteran - Female"