The Straw Hat Pirates are the main focus and protagonists of the anime and manga One Piece, called "Straw Hats" after Luffy's signature straw hat that was given to him by Shanks. Up until the Water 7 arc, they lived on a ship called Going Merry, however they are currently without a ship. The crew consists of seven members thus far. They are also referred to as the Mugiwara (straw hat) Pirates or the Luffy Pirates.

The Straw Hat crew stands out amongst pirate crews, or other evil people for various reasons. They never attack innocent people and always step in to stop an injustice. They are basically good guy pirates, led by their own sense of justice and their spirit of adventure, though they could care less about breaking the law, especially considering how Luffy said "I don't care about the world or about the government" during one of his encounters with the World Government's agents. In recent chapters, the Straw Hats declared war against the World Government, which may likely result in each member being given a bounty or having their bounties raised.

A shared trait of all of the Straw Hats is that they all have a dream they wish to fulfill, and a tragic past.

Each crewmate has their own dream to achieve. Some, like Chopper and Nami, are already doing so, while others, like Luffy and Zoro, are trying to reach a certain goal. It should be noted that all these dreams force them to travel the Grand Line.

• Luffy's dream is to become the Pirate King and raise a 'super' crew to back him up. To become the Pirate King, he must find Gold Roger's famed treasure, One Piece, which is inferred to be in Raftel. As for a crew, he has brought together so far six people who have caught his attention.
• Zoro's dream, shared with Kuina, is to become the world's greatest swordsman. To fulfil this dream, he must defeat every swordsman in the world, including the world's greatest swordsman Mihawk.
• Nami's dream is to draw a map of the entire world. She has already mapped all the areas that have been traveled, and it can be assumed that she will create a world map once the story is over. Also at the beginning of the story she was also trying to get 100,000,000 Berries in order to buy and save her hometown Cocoyashi Village from the clutches of the merman pirate Arlong.
• Usopp's dream is to become a brave warrior of the sea, much like his father, Yassop. For this to happen, he must become a strong enough sniper to be recognized. He also has an ambition of travelling to Elbaf, the warrior nation of the giants, and to see the great warriors that he idolizes so.
• Sanji's dream, shared with Zeff, is to find the All Blue, a legendary ocean. It is assumed to be in the Grand Line, and waters from all over the four seas gather there, bringing fish from all over the globe.
• Chopper's dream is to travel across the world, exploring with his friends and expanding his horizons. He also has an ambition to become a Panacea and be a doctor that cure any disease - even the one held by an entire country.
• Robin's dream is to find the Rio Poneglyph which tells the True History, continuing the research of her mother, Nico Olvia, and her old teacher and mentor, Professor Clover.
• Franky's dream is to create and travel with a dream ship which can reach the end of the Grand Line. He has created the ship which the Straw Hats are riding and it's his task to keep it in good condition.

In the beginning of the manga, Luffy claimed that he wanted at least 10 people to join his crew before entering the Grand Line. This was changed after Usopp told Luffy that after the "chef" joined them, they would rescue Nami and go to the Grand Line. Although this is long past the expiring date, it can still serve as evidence that there will be 10 or more Straw Hats at one point of the manga. Luffy also claimed in the beginning of the manga, that he will gather a crew strong enough to surpass his child hood hero Red-Haired Shanks.

Usually when he asks someone to join, Luffy is turned down completely. Later on the person in question will join anyways. The major exceptions to this rule are Usopp, who was thrilled to be asked to join and accepted immediatally, and Nico Robin, who invited herself into the crew and had to convince the others to let her stay. Luffy doesn't seem to mind if someone he wants to recruit has a profession or not. He allows Usopp to join, and later on names him the team's sniper, and considered Vivi a member even though she has no profession. He also offered Gaimon the chance to join his crew (which Gaimon tearfully turned down) when Gaimon had no apparent usfulness to the crew.

Though most adventures in One Piece are random, there seems to be a 'process' for recruitment. First, a situation arises where someone new is needed. The crew comes across someone who fulfills the criteria (i.e. Chopper the doctor, Nami the navigator). Luffy offers the person a position, and is usually turned down initially. Meanwhile, a situation arise where, some way or another, Luffy ends up battling a 'boss' character, and the would-be crewmate battles the underling (i.e. Luffy vs Don Krieg after Sanji battles Gin and Pearl), during which their backstory and dreams are revealed, thus convincing them to join the Straw Hat Crew. This process also fooled many fans into thinking Vivi would become a permenent crew member. The only crew members not following this process were Nami and Robin, both of whose history was revealed later on. Nami's official recruitment was when Luffy, Zoro, Usopp and Sanji defeated Arlong and his pirates. Robin was the first to initially willingly join, and her backstory has just recently been revealed.

If a Straw Hat crew member leaves the crew without Luffy's permission, Luffy usually does his best to recruit them back. First you can say to Luffy "I want to leave the crew", or not to agree with his decisions (Ex. Usopp wouldn't agree to Luffy's decision to abandon "Going Merry" and saying that he's too weak to stay in the crew). So far Robin and Usopp have both left the crew, Robin however rejoined it later. Usopp has officially left the Straw Hat crew, yet returned to the crew in his alias "Sogeking" to help rescue Nico Robin. It is yet unknown when, or if, he will truly rejoin the crew.