"Mr Brand, you have spoken very eloquently and movingly about the plight of my friend Andrew who was a dear friend to me," Sandiford wrote in a letter, urging Brand to help overturn her death sentence.
"I am truly heart-broken over his death...that is why I would like to ask for your help to support and promote my attempts to have a fair, final hearing into my own case."
Calling her situation "extremely urgent", Sandiford further wrote, reported The Independent: "If you can raise awareness of my case in any way it would be a great help and comfort to me."
Brand called for clemency for the Bali Nine Australian pair – Andrew Chan and Myuran Sukumaran, who were executed recently in Indonesia.
"To make a point ... successive Indonesian presidents demonstrate their power by increasing executions," said Brand in an eight-minute video on YouTube.
"It's a gesture, an empty gesture, a mask and a veil that conceals the corruption on Indonesia and the true nature of international drug smuggling ... that drug addiction and drug smuggling is an essential black economy – it's part of our global culture."
Sandiford, 58, from Cheltenham was convicted of smuggling cocaine worth £1.6 million from Thailand to Bali in May 2012, and faces death by firing squad.
"I don't want the macabre circus that went on last week in Nusa Kambangan. The prisoners' families were publicly humiliated while they waited for the executions to take place. The pictures of them crying in anguish are absolutely horrendous," said Sandiford.
Sandiford has maintained that she was forced into drugs' smuggling to protect her son whose life was at stake.
Indonesia is known for its tough penalties and zero-tolerance policy on drug offences.
Indonesia's President Jodo Widodo has defended the country's death penalty laws saying they act as an "important shock therapy" for future offenders.