Releasing its latest national poll, Fox News said Ms Clinton now garners 41 per cent to Mr Trump's 39 per cent, while Libertarian Gary Johnson receives 9 per cent, and Green Party candidate Jill Stein gets 4 per cent.
But in a two-way contest Ms Clinton leads by six points.
"The race for the White House has narrowed," Fox news said, adding that its latest poll finds that Trump is gaining ground in the head-to-head match-up, despite improvements from Ms Clinton on top issues.
"Trump has an opportunity to attract more support by moving off his hardline position on immigration. Nearly half of Johnson and Stein supporters say they'd be more likely to vote for him if he did," said Democratic pollster Chris Anderson, who conducts the Fox News Poll along with Republican pollster Daron Shaw.
As per RealClearPolitics, which keeps track of all major polls, Ms Clinton is now leading Mr Trump by 4.6 points.
Two days ago it was 6.1 points and about a month ago, Ms Clinton was leading on an average by nearly 10 percentage points.