The Magpies are keen to add to their squad on the final day of the January window, with Jonjo Shelvey on the verge of leaving for Nottingham Forest.
Newcastle are one of a number of clubs understood to be tracking Gallagher's situation at Stamford Bridge, with reports suggesting that he could be allowed to leave Chelsea amid their ongoing interest in Enzo Fernandez.
Everton have had a £45m bid for the England international rejected, but the 22-year-old's future remains uncertain ahead of today's 11pm deadline.
Eddie Howe is thought to be a big fan of Gallagher and The Telegraph reports that Newcastle are one of the clubs interested, but Chelsea are reluctant to let him leave for St James' Park on loan as they view the Magpies as a direct rival for European places this season.
Chelsea's £50m asking price for a permanent deal is reportedly more than Newcastle will consider paying this month, having spent £45m on Anthony Gordon from Everton already.
A summer deal could therefore be more likely for Howe's men, although the report claims that they are also considering a move for Loftus-Cheek to add to their squad for the remainder of the season.
The 27-year-old's wages are thought to be a stumbling block to any deal, though, with Loftus-Cheek currently on £150,000 a week at Chelsea.
Newcastle have also been linked with a move for Sheffield United's Sander Berge, although he is now expected to join Fulham instead.
The Magpies have already made one signing on deadline day, bringing in Harrison Ashby from West Ham United.