Iona Bryson has been given the honour almost 80 years after her grandmother, Agnes Yanetta.
Paying tribute to Iona, Annan Academy rector Jim Brown said: “I’m absolutely delighted for Iona.
“Her hard work was rewarded with As across the board — and a well deserved Intermediate Dux award.”
Mr Brown added: “She certainly represents an excellent role model to our aspirant young people in the lower school.”
Intermediate Dux is awarded to pupils who have completed S5, and the first years of their Highers, with Iona now in S6.
The fact that Iona’s grandmother was also similarly honoured so long ago also appeals to the rector.
He said: “I’m all about the history of this school, and the history here is fantastic.”
This year’s S6 Dux was Stevie Hall, who has now left the school.