This is one of three national polls to show Trump still on the top of the Republican field, despite showing some of his GOP rivals gaining on him.
Earlier on Wednesday, Trump said Fox News was not adequately covering his poll numbers, so he said he was ceasing all interviews and appearances on the channel for the "foreseeable future." Soon after his announcement, Fox said it had already canceled an upcoming appearance by Trump on "The O'Reilly Factor." Trump then spent Thursday interviews on CNN and MSNBC's "Morning Joe" complaining about the supposed lack of coverage.
In the Fox News poll, Trump led among likely Republican primary voters at 26 percent. Carson polled at 18 percent. Although she hit double digits in two national polls released Thursday, former technology executive Carly Fiorina didn't crack 10 percent.
Trump saw only a 1-point increase in support while Carson saw a 6-point jump from the August Fox News poll. Texas Sen. Ted Cruz, who was previously third, saw a 2-point drop in his support.
Among all voters surveyed, however, 28 percent said they believe former Secretary of State Hillary Clinton "will be the next President of the United States."
The poll was conducted among 1,013 registered voters from Sept. 20-22 by live cellphone and landline interviews. Among 398 Republicans surveyed, the margin of error was plus or minus 4.5 percent.