The TV chef has been treated in Newcastle since last week for an undisclosed condition, which was said not to be a brain tumour.
King was said to be "well on the mend" and will rest at home near Newcastle ahead of making a new series of the popular BBC cooking show he fronts with his friend Dave Myers.
The presenter's publicist said: "Si is going home today. He was in hospital where he has undergone a routine procedure. He will be resting for a while before filming begins on the next series of the Hairy Bikers.
"He thanks everyone for their best wishes."
He has lost four stone since last year when he topped the scales at around 19 stone by following a no-fat, small portion, low-carb diet.