Robert Pattinson, Justin Timberlake, Matt Damon, Halle Berry and thyroid cancer survivor Sofia Vergara also turned out at the sombre televised event to lend their support to the campaign, which was launched by late Spider-Man franchise producer Laura Ziskin. She lost her battle against breast cancer in 2011, but was remembered with a special video featuring tributes from film stars Tobey Maguire and Emma Stone.
In the clip, Stone said, "Like every great hero, she had a vision and she set us into motion. And now it's up to us to continue moving forward to achieve her dream."
Hollywood icon Douglas, who beat throat cancer last year (11), urged viewers to donate to help find a cure for the killer illness to save other victims of the disease.
He told the audience, "It picked a fight with the wrong guy!... Cancer didn't bring me to my knees, it brought me to my feet... I stand tonight because I want to be part of this effort to find an end to cancer. This is possible... Cancer's in for one hell of a fight."
Country singer Taylor Swift fought back tears as she debuted a new song called Ronan, inspired by a three-year-old boy named Ronan Thompson, who died of the illness last year (11). The tune was made available for download after the show, with all proceeds being donated to the cancer charity.
Alicia Keys and Tim McGraw also took to the stage during the telethon, while British rockers Coldplay dedicated their performance of Paradise from their concert in Paris, France earlier that night to the cause.
Meanwhile, a slew of stars including actress Felicity Huffman, True Blood hunk Joe Manganiello, comedian Ray Romano, basketball ace Kobe Bryant and gold medal-winning Olympic gymnast Gabby Douglas manned the phones and chatted to those calling in to pledge donations throughout the night.
Friday's event was produced by Paltrow, who took over the telethon from her pal Ziskin, and before the show, she opened up about losing her father Bruce to cancer in 2002.
She told reporters: "It's been almost a decade now and I'm sort of more used to the fact that he's not here in physical body. But I definitely feel his presence, and I think he would be really happy that I'm here tonight doing this and trying to spare other people from what he went through."
The amount raised from the telethon was not available as WENN went to press.
Paltrow has also announced plans to take her cancer crusade to London and stage a similar event in October (12).