Foley was kidnapped on Thanksgiving Day 2012 while covering the Syrian uprising. The Islamic State posted a Web video Tuesday showing his murder and said it was in retaliation for US airstrikes in northern Iraq.
President Obama has called Foley a hero for telling the stories of oppressed people in war-torn regions like Syria and Libya. The US launched a raid this summer to rescue Foley and other hostages, but special forces were unable to locate the captives.
The Mass at 2 p.m. Sunday is in Foley's hometown church, Our Lady of the Holy Rosary in Rochester.
At a vigil Saturday night in Rochester, about 200 people gathered to show support for the Foley family. Foley's parents, John and Diane Foley, attended, Foster's Daily Democrat reported.
"We are honored that you care and love Jim. We are honored that you recognized the sacrifices he made," John Foley said. "He loved the Syrian people. He was devoted to telling their story and doing whatever he could to help their fight."
Speakers praised Foley's determination to report on the Syrian people uprooted by conflict.
"Tonight we want to honor freedom and love: the freedom that James so vehemently believed that all people deserved," said Nadia Alawa, founder of NuDay Syria, a Massachusetts-based organization working to ease the pain and loss in Syria. "To James Foley, denying others freedom and a basic voice of feelings and free space was not OK."
She also condemned the campaign of terror and violence carried out by the Islamic State.
"(ISIS) thrives on using the name of Islam to justify their vengeful acts that targets innocent non-Muslims as well as Muslims for no apparent, rational reasons," Alawa said. "As a Muslim, I refuse to let terrorists take my religion as hostage."
In the days since the release of the chilling video of his beheading, Foley's friends and family have sought to replace that grisly image with their memories a brave journalist, determined to shed light on the stories of the Syrian people.
"We have never been prouder of our son Jim," Diane Foley wrote on his Facebook page. "He gave his life trying to expose the world to the suffering of the Syrian people."