In North Carolina, Clinton gets support from 45 percent of likely voters, Trump gets 41 percent, and Libertarian Gary Johnson gets 9 percent. (The Green Party's Jill Stein didn't qualify to make the ballot in the state.)
In a two-way race, Clinton's lead expands to five points, 48 percent to 43 percent.
In Ohio, Trump holds a one-point advantage over Clinton among likely voters, 42 percent to 41 percent, with Johnson at 9 percent and Stein at 4 percent, although that margin is inside the poll's margin of error.
Clinton and Trump are tied in a two-way race in the Buckeye State — 45 percent to 45 percent.
Trump's best path to get the 270 electoral votes needed to win the White House is by sweeping North Carolina and Ohio, as well as Florida and Pennsylvania.
But in the NBC/WSJ/Marist polls released of all four states this month, Trump leads or is tied in just one of them — Ohio.
The new NBC/WSJ polls of North Carolina and Ohio were conducted Oct. 10-12, after Sunday's second presidential debate, as well as after 2005 audio surfaced of Trump using lewd language to describe kissing and groping women.
North Carolina's downballot races are deadlocked
Down the ballot in North Carolina, incumbent Republican Sen. Richard Burr is tied with Democratic challenger Deborah Ross among likely voters, 46 percent to 46 percent.
In North Carolina's gubernatorial race, incumbent GOP Gov. Pat McCrory gets support from 48 percent of likely voters, while Democratic challenger Roy Cooper gets 49 percent.
In Ohio, incumbent GOP Sen. Rob Portman holds an 18-point lead over Democratic challenger Ted Strickland, 55 percent to 37 percent.
The NBC/WSJ/Marist poll of North Carolina poll was conducted Oct. 10-12 of 1,025 registered voters (which has a margin of error of plus-minus 3.1 percentage points) and of 743 likely voters (plus-minus 3.6 percentage points).
The NBC/WSJ/Marist poll of Ohio was conducted Oct. 10-12 of 1,007 registered voters (plus-minus 3.1 percentage points) and 724 likely voters (plus-minus 3.6 percentage points).