The branch, which is currently open for three half days per week, will permanently close on November 17.
It says the number of customers visiting branches has fallen considerably in recent years as more choose to do most of their everyday banking online.
Russell Galley, director of consumer relationships at Lloyds Banking Group, said: “Our customers have more choice than ever in how they bank with us.
New gin trail launched with 43 stop off points in Blyth, Seaton Delaval, Whitley Bay, Tynemouth and North Shields
Councillor urges public 'not to worry' about proposed Britishvolt factory in Cambois, and insists construction is on schedule
New dog walking business created in Ancroft
Glendale Engineering expansion plan approved
Active Northumberland offers apprenticeships at Morpeth and Alnwick leisure centres
"As our customers do more online, visits to some branches have fallen by as much as 85% over the last five years.
"Alongside our digital, online and telephone services, we'll continue to invest in our branches, but they need to be in the right places, where they're well-used.”
For a short period of time after the branch closes Lloyds also plan to have a community banker visit.
Cllr Steven Bridgett, Rothbury ward member, posting cryptically on social media, said: “I have heard rumbles for some months now that there was the possibility of Lloyds Bank in Rothbury closing.
“I cannot go into further detail at the moment but where one door closes, another opportunity may be on the horizon, which I will hopefully have further details of in due course.”