Supporters are encouraged to take the Spirit Day Pledge at glaad.org/spiritday .

College student Jordan Addison, who recently shared his experience with anti-gay bullying on The Ellen DeGeneres Show; Shane Bitney Crone, whose web video about the tragic death of his partner has garnered millions of views; anti-bullying advocate Brittany McMillan; advocate and writer Tiq Milan; transgender advocate, author of Fish Food: A Memoir and former People.com editor Janet Mock; Ohio mom Jennifer Tyrrell, who was ousted as leader of her son's Boy Scouts troop because she's gay; and Scouts for Equality founder and author of My Two Moms, Zach Wahls will participate alongside Hilton, Jogia, Mitchell, O'Neal, Takei and Williams as Spirit Day Ambassadors.

The Los Angeles Unified School District (LAUSD), the nation's second largest school district with more than 640,000 students in over 900 schools, will participate by sharing information about Spirit Day with students on its website and through its social media channels. The National Basketball Association (NBA) and Women's National Basketball Association (WNBA) will also participate through social media.

Corporations including AMC Entertainment, AT&T, CNBC, Caesars Foundation, Carat, Citi, Delta Air Lines, Draftfcb, Facebook, Hewlett-Packard Company, The McGraw-Hill Companies, Omnicom Group, Publicis Kaplan Thaler, Publicis Groupe, Toyota Financial Services, Warner Bros., and Yahoo! will also participate in Spirit Day. Participating companies will distribute information to employees about wearing purple and/or turn their logo purple on October 19.

Participating national landmarks include the LAX Pylon Lights and the JFK traffic tower, both of which will turn purple on October 19.

Local and national groups and organizations including the BULLY Project; Campus Pride; FriendFactor; the Gay, Lesbian & Straight Education Network (GLSEN); GSA Network; the National Bullying Prevention Center by PACER; Parents, Family and Friends of Lesbians and Gays (PFLAG); Reaching Out MBA; Straight But Not Narrow; The Trevor Project; and Youth Empowered to Act (YETA) will all participate by wearing purple on October 19, turning their social media channels purple, and encouraging members to participate.

For a complete list of celebrity participants, media outlets, TV networks, organizations and corporations visitglaad.org/spiritday. Additional participants to be announced.

In 2010, teenager Brittany McMillan called on her friends to wear purple as a way to memorialize those who lost their lives to bullying. With GLAAD's help, Spirit Day has since garnered widespread support from celebrities, TV news and entertainment programs, corporations, organizations, schools, local communities, and even national landmarks. Spirit Day coincides with GLSEN's Ally Week, as well as National Bullying Prevention Month.

"Showing support for your friends, family and teachers can make all the difference in the world to young LGBT people, whether they are going through a tough time or not," said 17-year-old McMillan. "This year, Spirit Day is going to be bigger and better than ever, and I'm so thrilled to be going purple alongside some of my favorite celebrities, as well as millions of others in a united stand against bullying."

"By going purple for Spirit Day, millions of Americans are helping to send a clear message that no one should be bullied simply because of who they are," said GLAAD President Herndon Graddick.

Among those who participated in 2011: hosts of the Today Show, Good Morning America, Live! With Regis & Kelly, The View, CBS Evening News, NBC Nightly News, and ABC World News; celebrities including Tyra Banks, Cher, Ellen DeGeneres, Ricky Martin, Julianne Moore, and Oprah Winfrey; corporations like AT&T, Goldman Sachs, Facebook, MTV, and NBCUniversal; and national landmarks including Times Square, LAX, and the White House.