The actor, also famous for his role in Taxi, died on Friday (27May11) after spending two weeks in hospital fighting pneumonia and a blood poisoning condition called sepsis.
The 60 year old had fought an addiction to painkillers for several years and was originally believed to have taken a drug overdose, a claim which was vehemently denied by his publicist.
His Grease pal John Travolta was among the first to remember the actor, and now Newton-John, whose sister Rona was married to Conaway for five years, has released a statement about the tragedy.
She says, "It's so very sad. Jeff had a good heart and was so very talented. He was a big part of our family for many years and he will be missed."
The Australian actress introduced her sister to Conaway after wrapping Grease, and the pair married in 1980. They went on to have a son together but divorced after five years.