Evans passed away on Wednesday at the age of 48.
Announcing the news on their official website, the group says: "It is with profound sadness that we announce the passing of longtime Lynyrd Skynyrd bassist Ean Evans.
"Ean put up a valiant battle with an aggressive form of cancer and he will be sorely missed by family, friends and fans."
Evans joined the band in 2001 as a replacement for Leon Wilkeson, who was found dead in his hotel room in July that year after suffering from chronic liver disease.
It is the latest tragedy to hit the group - Powell suffered a suspected fatal heart attack in January.
Evans is survived by his wife Eva and their two daughters, Sydney and Andrea.