Hollywood actors Brian Cox and Alan Cumming, TV presenters Lorraine Kelly and Carol Smillie and singer Sharleen Spiteri are among the stars who have been recorded on tape, along with First Minister Alex Salmond and Labour leader Johann Lamont.
The historic change in the law will be set in motion this week when a bill is published in the Scottish Parliament.
The controversial move has met with opposition and a number of religious groups have united behind the Scotland for Marriage opposition body.
The law is almost certain to be introduced, but it is expected that some MSPs from across the party political spectrum will oppose it when it goes through the Holyrood legislative process after the summer. Equal marriage supporters featured in the video campaign include the First Minister and the leaders of all five main opposition parties in Scotland, as well as religious ministers from the Church of Scotland, the Scottish Episcopal Church, the Quakers, Unitarians, the Metropolitan Community Church, and Liberal Judaism.
Other celebrities taking part include Lord of the Rings star Billy Boyd, Sylvester McCoy, John Michie, Michelle McManus, Susan Calman and the Proclaimers, to the sound track of the song Pride by Amy MacDonald.
Tom French, policy co-ordinator for the Equality Network, said: “We’re proud of the ‘It’s Time’ video campaign, which demonstrates the breadth of support that exists for equal marriage in Scotland, and reflects the values of equality and compassion that have always been at the heart of our society.
“We hope that in the coming months MSPs will vote by a clear majority to give same-sex couples an equal right to celebrate their love and, in doing so, they will send out a strong message to the world about the kind of fair and progressive country we want Scotland to be.”
Cumming, the award-winning Hollywood actor, said; “I wanted to take part in the Equality Network video campaign because as a Scot.
“I feel our country should be aware of the inequality that exists, as we are not a nation to discriminate.”
A statement from Scotland for Marriage stated: “Scotland for Marriage is backed by both religious and non-religious groups. It is an expression of the breadth of concern within Scottish society.”