It is normal for new actors who haven't proven themselves to audition for roles in movies. But What about A-listers like Tom Cruise, Brad Pitt, etc. Do these guys still attend auditions or are scripts just handed to them because they already have the image that fits the character in the movie?
Sometimes they have to give an audition and sometimes they don't have to give an audition.
If you count Russell Crowe as A-lister then he also gave an audition for the film version of the musical Les Miserables. (Source: www.dailymail.co.uk). There are many other examples over the internet. Even sometimes non-A-listers can also clear auditions over A-listers but an A-lister may get more attention in auditions.
Scarlett Johansson Auditioned for Les Miserables With Laryngitis & Lost to Anne Hathaway. For this case it looks like one A-lister lost the role to another A-lister.
I'm not sure about Hollywood but in Bollywood sometimes movies are made for an A-lister, so in that case they don't need to give an audition.
It appears to depend on the film's creators and what they want. E-Online were asked about this via Twitter and published an article as a response, which included this snippet:
Most of the time, A-list gods and goddesses don't have to read for anything. In fact, even B-plus talent often joins a project before a casting director is even hired.
They concluded their article with this information:
And that's what happens with many famous actors: a meeting, usually a lunch, where the director or producers can size up an actor without making the talent feel like they're under evaluation [is all that is needed].
Now obviously, E is just a single source of information, but given their role as one of the leading media providers of celebrity news their articles should carry weight on the issue.
An interesting example of this comes from this article, which discusses how an at-the-time fairly unknown Jake Gyllenhaal "bombed" his audition for the Lord of the Rings trilogy (to play Frodo). The article states:
Gyllenhaal isn't the only major actor who was discussed as a possibility for Jackson's blockbuster trilogy. Daniel Day-Lewis was one of the first actors that Jackson sought to play Aragorn, but Day-Lewis passed on the opportunity. Russell Crowe was also offered the role of Aragorn, but he passed as well.
In perhaps the most famous bit of "Lord of the Rings" almost-casting, Sean Connery was chosen for the part of Gandalf. "I never understood it. I read the book. I read the script. I saw the movie. I still don't understand it," Connery said about why he decided against starring in "Lord of the Rings."
This seems to suggest that all three of these A-List celebrities were offered roles in the movie after reading the script, but not after auditions. Clearly, they had the reputation to warrant immediate casting, whereas Gyllenhaal (who at the time was much less known) didn't.
Some actors don't get roles, despite expecting them, because they refuse to audition. For example Beyonce in The Princess and the Frog.
Finally, there are times that famous celebrities are offered roles in films that were in effect created especially for them. In these situations, it seems unlikely they would need to audition, as it's the strength of their previous work that has attracted the attention of the film's creators.
As a final, final note, this article is an interesting read. It basically tracks the chronological order in which the movie Gravity approached people for the various roles on offer, before finally setting on George Clooney and Sandra Bullock as lead stars.
The other two answers here are pretty solid, but I wanted to touch on the sort of "cliques" that exist in Hollywood as well.
Take many of the Judd Apatow movies for example. There is an established group of cast members from movie to movie. You get the sense that the roles they play may not necessarily designed for them, but that the genre of movie is so niche that every character is the one they were "born to play". For example, James Franco and Seth Rogan are often portrayed as the carefree stoner types. This, to me, is the result of actors with established characters, mixing with a group of people whose movies revolve around subjects pertinent to those characters.
Adam Sandler's films also do this, where a role may not be designed for someone, but rather that person is just part of the group and they are slotted in where they fit the best. Dan Patrick and Dave Matthews have cameo appearances in several of Adam Sandler's movies and actors such as Rob Schneider and Peter Dante are always finding themselves with a part.
Now, these aren't all "A-list" celebrities, but it does go to show other factors in casting that don't revolve around auditions or specific role creation.