The Bathgate star, whose career has soared to new heights with the recent success of hit tune Someone You Loved, made the announcement on Twitter on Wednesday evening.
And fans reacted with a number of suggestions at what the 9am big reveal could be.
One fan urged the star to head to Yorkshire, saying: "Some more Sheffield dates would be HIGHLY appreciated cause I didn't get tickets last time" while another suggested "Performing before Scottish Cup Final wearing Hearts Strip."
One fan asked, with tongue firmly in cheek: "You becoming a potato smiley?????"
He recently announced he would be playing in Bathgate at Glenmavis Tavern at 9pm today before heading to Glasgow on April 21 to play 1pm, 6pm and 9pm gigs on April 21.
In a tweet announcing the announcement, Capaldi said: "UK HAVE AN ABSOLUTELY F****** INSANE ANNOUNCEMENT AT 9AM. C U TOMORROW (today)"
Check back at 9am to find out what the big reveal is.