user2429: The moves 1. e4 c5 2. Nc3 Nc6 3. f4 characterize the Grand Prix Attack in the Sicilian defense.
     [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

     1. e4 c5 2. Nc3 Nc6 3. f4

How did the Grand Prix Attack get its name? 

user33991: Whilst the other answers are not wrong, I'd like to draw specific attention to FM David Rumens, who won a series of Grand Prix tournaments in the 70s and 80s using this "Grand Prix" opening.
He always said it was his favourite opening to play against the Sicilian and it's not unreasonable to suggest that the name came about due to his success with it.
He taught me chess as a child and was a phenomenal mentor and character and I don't see enough references to him in discussions about the Grand Prix.

user1105: From this page, I quote

The Grand Prix Attack got its name from the many strong British
  players who used it on the Grand Prix Circuit in the 1980's

As Remco Gerlich said, It was used by British players on the British Grand Prix circuit. Weekend tournaments that also have a combined standings.

2429: <p>The moves 1. e4 c5 2. Nc3 Nc6 3. f4 characterize the Grand Prix Attack in the Sicilian defense.</p>

<pre><code>     [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

     1. e4 c5 2. Nc3 Nc6 3. f4
</code></pre>

<p>How did the Grand Prix Attack get its name? </p>
 33991: <p>Whilst the other answers are not wrong, I'd like to draw specific attention to FM David Rumens, who won a series of Grand Prix tournaments in the 70s and 80s using this &quot;Grand Prix&quot; opening.</p>
<p>He always said it was his favourite opening to play against the Sicilian and it's not unreasonable to suggest that the name came about due to his success with it.</p>
<p>He taught me chess as a child and was a phenomenal mentor and character and I don't see enough references to him in discussions about the Grand Prix.</p>
 1105: <p>From <a href="http://www.chess.com/blog/JCQuinones/closed-sicilian-grand-prix-attack-b23">this page,</a> I quote</p>

<blockquote>
  <p>The Grand Prix Attack got its name from the many strong British
  players who used it on the Grand Prix Circuit in the 1980's</p>
</blockquote>

<p>As Remco Gerlich said, It was used by British players on the British Grand Prix circuit. Weekend tournaments that also have a combined standings.</p>
