The Duchess was greeted by scores of locals outside the Victoria Gallery and Museum in the city centre when the woman reached over the barrier to lovingly embrace her.
According to UK newspaper the Express, Prince Charles' wife initially 'froze with shock', and in keeping with royal protocol, did not return the well-wishers' hug, but smiled appreciatively and moved on to greet others.
With the fan's embrace clearly just a loving act and not a security issue, Camilla had nothing to fear - but the non-traditional greeting perhaps came out of the blue for the stiff-upper-lip royal, who nonetheless didn't seem too concerned.
The 71-year-old Duchess buttoned up against the British chill in a blue calf length coat, black boots and black gloves.
Charles and Camilla are in Liverpool to meet Irish President Michael D Higgins and his wife Sabina at Liverpool University, which both men are patrons of.
The starstruck royal fan, who can be named as MoonSunKim of Korea, told the Liverpool Echo the moment will be 'a very good memory' which she will 'never forget'.
'I was so excited and I never saw the royal family before,' she said.
'I just told her 'Nice to meet you, I'm from Korea' and she said 'Nice to meet you as well'.'