Whoa.
During an interview with Australian TV show, John bristled at the mere mention of the singer, saying, "She's such a nightmare. Her career's over."
He didn't stop there, ranting that "she looks like a f--king fairground stripper" and ripping her recent gun-pulling stunt and dance-pop catalog.
"If Madonna had any common sense she would have made another record like Ray of Light," he added, "and stayed away from the dance stuff."
The 65-year-old John said that the Queen of Pop should "just be a great pop singer and make great pop records, which she does brilliantly."
John's beef, or at least the latest iteration of it, may stem from her quasi-feud with Lady Gaga, godmother to Elton's 19-month-old son, Zachary.
"[Madonna's] been so horrible to Gaga," John told Sunday Night.
In May, Madonna performed a curious mash-up of "Born This Way" and "Express Yourself" that many saw as a Lady Gaga diss, not a tribute.
John's feud with Madge goes back to 2004, when he accused her of lip-syncing, a point he reiterated earlier this year before the Super Bowl.
Elton's husband, David Furnish, has also gone off on Madonna.
Choose your side in this ongoing celebrity feud: