There have been reports during the transfer window that La Liga giants Barca are closing in Dembele, 20, and speculation has only intensified with Paris Saint-Germain targeting Neymar.
But Dembele – under contract until 2021 after arriving from Rennes in 2016-17 – does not want to leave Signal Iduna Park, having scored six goals and supplied 12 assists last season.
"To be honest, this speculation doesn't interest me at all," he said.
"I like being here in Dortmund and I decided to join Dortmund after my time at Rennes consciously."
Dembele is set to link up with star Dortmund team-mate Pierre-Emerick Aubameyang again in 2017-18.
Aubameyang was tipped to leave amid interest from AC Milan and China but last season's top scorer in the Bundesliga is now expected to remain at the club.
Dembele said: "I'm happy that he will continue playing for us. He's like a brother to me."