The 60-year-old singer is reportedly set to perform two songs in Tel Aviv on May 18, including a classic track and a new single.
Madonna's decision to appear, confirmed by a representative, could prove controversial after stars including Pink Floyd's Roger Waters called for a boycott.
It said: "We, the undersigned artists from Europe and beyond, support the heartfelt appeal from Palestinian artists to boycott the Eurovision Song Contest 2019 hosted by Israel.
"Until Palestinians can enjoy freedom, justice and equal rights, there should be no business-as-usual with the state that is denying them their basic rights."
Other signatories include novelist Yann Martel, actress Julie Christie, writer and director Peter Kosminsky and British band Wolf Alice.
The 2019 Eurovision Song Contest is due to be held in Israel after the 2018 contest was won by Israel entry Netta with her song Toy.
The UK's entry is singer Michael Rice.