Steve Claus is the oldest son of Malcolm and Margaret Claus, the older brother of Arthur, the grandson of Grandsanta and one the main characters and the former main antagonist of Arthur Christmas. He is voiced by Hugh Laurie. He does however, not to anything relate, in fact deep down, he does love his family dearly, it's just that he seems to make more of a control in how to run christmas through his more business-oriented plans.
At the beginning of the film, Steve is the head of mission control with other elves and is helping Santa, [Malcolm Claus] his father to complete the Christmas operation that he is mainly the brains behind. As Malcolm is a little slow on the study of technology and modern tools used to complete the Christmas deliveries, Steve is the one who helps him through the whole night, who, surprisingly, Malcolm Claus takes most of the credit for.
As Steve is ready to have the part of Santa Claus as Malcolm is nearly retired, he was obviously shocked and sad when his father said that he is prepared for another year!