There are a lot of people who have won the Oscars for their first role. It will be hard to count and enumerate each one of them. It seems that people have usually gone through a lot before they have bagged the role that will make them become popular. There are a lot of starting actors and actresses who need the recognition that they deserve.
Of course, there are also some who have gained popularity not because they are good but because they are always present in various movies and television shows. Those who win the Oscar will not necessarily have a long career but it will always be an achievement that a lot of people will not forget.
Over 20 people have won Oscars for their first role. While every actress and actor have fantasies of gaining immediate star status when they first break on to the Hollywood scene or into the film industry, the vast majority of people do not actually acheive this for their first role.
It is a lot more common that budding actors and actresses will need to gain some very valuable experience in the industry before slowly shaping themselves into the kind of people they want to be in show business. For a few lucky individuals, they can begin their career much faster and easier by winning both an Oscar winning role in a film and by already having the talent necessary to achieve such an incredible honor.