They said the 12-year-old was ambushed on Wednesday by several settlers near his home at Qaryot village outside the Palestinian-ruled city of Nablus. He was stabbed 11 times, paramedics said.
Palestinians who seek statehood in the West Bank and Gaza Strip have complained of frequent harassment and attacks by settlers during four and a half years of fighting.
About 240,000 settlers live in settlements among 3.6 million Palestinians.
An Israeli police spokesman said the Qaryot stabbing was under investigation.