The 'Only the Horses' band will headline the Americas stage at the famous landmark as part of the BT River of Music event on the weekend of July 21 to 22.
Singer Ana Matronic revealed that the group are planning to dress up for the occasion.
"I think the Tower of London is begging for thematic dress or Elizabethan drag perhaps," she told BBC Breakfast.
"Or perhaps famous inhabitants of the Tower. I was thinking of dressing [Babydaddy and Del Marquis] as the two princes."
She added that she has a personal interest in British history, saying: "I have British heritage, my first traceable ancestor is Welsh, I also have Cornish and Irish heritage."
Scissor Sisters release their fourth studio album Magic Hour today (May 28), with frontman Jake Shears explaining that it is a "happy" record: "It's a really happy album, we had so much fun making it. I can't believe it's out today, I'm very excited."
Speaking about the band's moods while recording albums, he said: "There's always times that are easier than others. Sometimes it's very difficult and you can't take for granted the moments where the songs are coming and it's growing.
"This record we made so fast, we started in September, and finished by the end of December."
Shears also stated that he would prefer to release a succession of EPs instead of full albums, in order to get their music out to fans quicker, commenting: "It makes more sense to me to put out EPs. We've been eking out songs by January. We've been given fans stuff to listen to."
Scissor Sisters will embark on a UK and Ireland tour from October.
Watch the video for 'All the Horses' by Scissor Sisters below: