Japan's biggest daily Yomiuri found that support for Abe's government had risen to 58 percent from 53 percent in January. The paper surveyed 1,054 people by telephone on Friday and Saturday for the poll, which was the first since the hostages were killed.
A separate poll released by Kyodo on Saturday also showed an increase in support for Abe. More than 60 percent of respondents said they approved of the government's response to the hostage crisis.
Islamic State militants beheaded journalist Kenji Goto last month, a week after the group released footage appearing to show the beheaded body of another Japanese hostage, Haruna Yukawa.