The Australian star, perhaps best known for playing Dame Edna Everage, passed away on Saturday at St Vincent's Hospital in Sydney. He was 89.
Following the sad news, Elton took to Instagram to post a throwback photo of him and Barry dressed as Dame Edna during a TV appearance.
"Barry was the funniest man ever. AND, the sweetest man ever. What a sad day," he wrote.
In his own tribute, Ricky simply tweeted, "Farewell, Barry Humphries, you Comedy genius."
Elsewhere, Andrew Lloyd Webber expressed his sadness over Humphries's passing.
"Farewell dearest Barry. No more will we share obscure composers and unfashionable Victoriana. How I'll miss you," he commented.
And Rob Brydon revealed that he had spoken to Humphries just last week.
"RIP Barry Humphries. A true great who inspired me immeasurably. It was a delight to call him my friend. I've been in Australia and was with him only 3 days ago. He was, as ever, making me laugh. His talent shone until the very end. My love goes out to Lizzie and all the family," he wrote on Twitter.
Meanwhile, Australian Prime Minister Anthony Albanese called Humphries "an absolute one-of-kind" and former talk show host Michael Parkinson shared that the comedian was one of his all-time favourite guests.
"I have lost a dear friend of many years," he said in a statement to The Press Association. "Barry was a cultured, highly intelligent, fascinating man who just happened to create, in Dame Edna Everage, one of the everlasting comedy characters of all time as well as one of my favourite guests on my talk show.
"In a time when the word is bandied around far too easily, we have truly lost a genius. I shall miss him and the dame in equal measure."