The woman, believed to have stopped off at the town’s Morrisons store en route for Cumbria, had a three-figure sum of money snatched off her on Saturday night by the teenager, accompanied by four other youths.
The culprit ran off from the Mart Street shop in the direction of Arthur Street.
Police were contacted and officers carried out a search, but the offender was nowhere to be found.
The woman targeted was said to have been left distraught by the theft, carried out at about 9.50pm.
Hawick and Hermitage councillor Davie Paterson has expressed his dismay at the theft, saying: “It’s ridiculous, for goodness sake.
“I think Morrisons have actually brought in some extra security guards because there has been that much bother with youngsters causing a nuisance there, making a lot of noise and thieving.
“I think it’s absolutely appalling. You hear about this in some harder areas of Scotland but not in Hawick – never in Hawick. It’s disgusting.”
The theft has also sparked outrage on social media and calls for action to stop gangs of youths gathering outside the shop.
Pamela McLean posted: “There’s always a crowd outside or hiding in the kids’ toilet. When staff tell them to get out of the shop, they get nothing but abuse.
“It’s very intimidating when I go in there on my own.”
Susan Patterson added: “It’s getting worse. There’s always a group hanging about, intimidating folk as they go.”
Edward Beattie said such incidents could only reflect badly on the town, explaining: “This woman will be going on to Carlisle and telling people there she was robbed at a cashpoint in Hawick by kids. That’s not good for the town.”
Police investigating the theft are appealing for potential witnesses to come forward.
A Police Scotland spokesperson said: “Police in the Borders are investigating after a three-figure sum of money was stolen from a woman at an ATM in Mart Street in Hawick at around 9.50pm on May 4.
“The suspect is described as male, aged 16 to 18, with dark hair, wearing a dark-coloured tracksuit with a single white stripe on the sleeve and last seen in the Arthur Street area.
“He had been in the company of two other males and two females of similar age.
“Anyone with information can call Police Scotland on 101, quoting incident number 4,489 of May 4, or report it anonymously to Crimestoppers on 0800 555111.”