Martin Sheen will deliver a eulogy at the funeral of Sister Mary Campbell, his "dear friend" in Mayo later this week.
Sister Campbell originally from Kiltimagh, County Mayo, was killed in a car crash in Malibu, California. She was one of two passengers killed in the crash. The car was driven by the United States ambassador to Malta, Doug Kmaic. Kmaic avoided serious injury.
Martin Sheen's was one of the first cars at the scene of the accident. He was travelling with his son, Emilio Estevez.
Sheen family representatives have said that Martin will speak on Thursday at Sister Campbell's funeral Mass at the Church of the Holy Family, Kiltimagh.
Sister Campbell was 75-years-old. In 2003 she had retired from the position of principal and schoolteacher. She will be buried at Kilkinure cemetery.