The actor, who plays Josh Ashworth, was told he had earned three As and a B on Thursday at his Rossall private school in Blackpool.
Flood said he only attends 20 per cent of lesson time but was still top of his year.
He explained: "I have been at the school since I was a nipper and so when I spoke to the headmaster about balancing my school work with my job, he was really understanding.
"When I was offered the part, I knew it was not something I could pass up. It was sometimes difficult to manage both things. I would usually only make it into school on average about one-and-a-half-times a week.
"Sometimes I would be working full-time for about four weeks and wouldn't get a chance to go near school. Then I would have two solid weeks of classes in school."