Izac Thorne, of Harrington Road, Bridlington, was sentenced to 40 months behind bars for the robbery which occurred last November.
He was given the sentence at Hull Crown Court last Friday, January 24.
On Monday November 25 2019, Thorne walked into Sewerby Road convenience store in Bridlington brandishing a knife.
He demanded money, before pushing a member of staff into a wall and stealing alcohol from the store.
Detective Sergeant Dave Porteus, from Humberside Police's Criminal Investigation Department, said: “Thorne committed a serious offence without care or consideration for his victims.
“I can only imagine how frightening the ordeal must have been for those in the shop at the time of Thorne’s attack and I want to thank them for their cooperation throughout our investigation.
“I hope this sentence sends a clear message to anyone considering committing a similar offence, we will bring you to justice.”
Thorne was given a 40 month sentence for robbery with a concurrent 12 month sentence for possession of an offensive weapon.