Roronoa Zoro, also known as "Pirate Hunter" Zoro, is a main combatant of the Straw Hat Pirates, one of their two swordsmen, one of the Senior Officers of the Straw Hat Grand Fleet, and is publicly recognized as the right-hand man of his crew's captain Monkey D. Luffy. Formerly a bounty hunter, he is the second member of Luffy's crew and the first to join it, doing so in the Romance Dawn Arc.

Born in the East Blue, Zoro is the son of Tera and Roronoa Arashi, the grandson of Shimotsuki Furiko and Roronoa Pinzoro, and the grandnephew of Shimotsuki Ushimaru, making him a descendant of both the Shimotsuki Family of Wano Country and the legendary samurai, Shimotsuki Ryuma. As a master of Three Sword Style, a swordsmanship style which he created during his childhood training in Shimotsuki Village, Zoro is one of the three most powerful combatants of the Straw Hats, alongside Luffy and Sanji, who are referred to as the "Monster Trio". 

His dream is to become the greatest swordsman in the world, in order to honor a promise he made to his deceased childhood friend and distant cousin Kuina.

"Cat Burglar" Nami is the navigator of the Straw Hat Pirates and one of the Senior Officers of the Straw Hat Grand Fleet. She is the third member of the crew and the second to join, doing so during the Orange Town Arc. She is the adoptive sister of Nojiko after the two were orphaned and taken in by Bell-mère.

She was formerly a member of the Arlong Pirates and initially joined the Straw Hats so that she could rob them in order to buy back her village from Arlong. However, she legitimately joined the Straw Hats after they rebelled against and defeated Arlong. Her dream is to make a map of the entire world.

She first gained a bounty of Beli16,000,000 following the raid on Enies Lobby. It later increased to Beli66,000,000 after the Dressrosa Arc. Following the Raid on Onigashima, her bounty was increased to Beli366,000,000.

"God" Usopp is the sniper of the Straw Hat Pirates and one of the Senior Officers of the Straw Hat Grand Fleet. He is the fourth member of the crew and the third to join, doing so at the end of the Syrup Village Arc. Although he left the crew during the Water 7 Arc, he rejoined at the end of the Post-Enies Lobby Arc.

Usopp is the son of Yasopp and the late Banchina. He was born and raised in Syrup Village, serving as "captain" of the Usopp Pirates and being Kaya's close friend. After working with the Straw Hats to defeat Kuro and the Black Cat Pirates, he was invited to join the crew. Despite his usual cowardice, Usopp dreams of becoming a brave warrior of the sea just like his father and lives every day in pursuit of living up to this dream.

He first gained a bounty of Beli30,000,000 under his Sogeking Persona after the incident at Enies Lobby. After the Dressrosa Arc, Usopp gained a bounty of Beli200,000,000 under his own name. Following the Raid on Onigashima, his bounty was increased to Beli500,000,000.

"Black Leg" Sanji, born as Vinsmoke Sanji, is the cook of the Straw Hat Pirates and one of the Senior Officers of the Straw Hat Grand Fleet. He is the fifth member of the crew and the fourth to join, doing so at the end of the Baratie Arc.

Born as the third son and fourth child of the Vinsmoke Family (thus, making him a former prince of the Germa Kingdom), he disowned his family twice, once in his youth and again after reuniting with them as an adult. After fleeing the Vinsmokes as a child, he eventually entered the care of Zeff as the sous chef of the Baratie, where he would remain until he met Monkey D. Luffy, who convinced him to join his crew. He is one of the top three fighters of the Straw Hats, alongside Luffy and Zoro, who are referred to as the "Monster Trio".

He first gained a bounty of Beli77,000,000 for his role in the raid on Enies Lobby. It increased to Beli177,000,000 after the Dressrosa Arc, but the condition of his bounty was changed to Only Alive due to his biological father's interference. After he escaped from Big Mom's territory, his bounty condition was reverted back to Dead or Alive (with the Vinsmoke name despite his renouncing it), and its value increased to Beli330,000,000. Following the Raid on Onigashima, his bounty was increased to Beli1,032,000,000.

Tony Tony Chopper, also known as "Cotton Candy Lover" Chopper, is the doctor of the Straw Hat Pirates and one of the Senior Officers of the Straw Hat Grand Fleet. He is the sixth member of the crew and the fifth to join, doing so at the end of the Drum Island Arc. He was temporarily forced to join the Foxy Pirates during the Long Ring Long Land Arc, but was quickly returned to Luffy's crew.

Chopper is a reindeer that ate the Hito Hito no Mi, a Devil Fruit that allows its user to transform into a human hybrid at will. He was taught medicine on Drum Island by his two parental figures, Doctors Hiriluk and Kureha. Chopper aims to travel all across the world in the hopes of accomplishing his dream of being able to cure any disease.

He gained his first bounty of Beli50 after the incident at Enies Lobby, having been mistaken for the Straw Hats' pet. After the Dressrosa Arc, it was increased to Beli100, then to Beli1,000 following the Raid on Onigashima.

Nico Robin, also known by her epithet "Devil Child" and the "Light of the Revolution", is the archaeologist of the Straw Hat Pirates and one of the Senior Officers of the Straw Hat Grand Fleet. She is the seventh member of the crew and the sixth to join, doing so at the end of the Arabasta Arc. She temporarily left the crew during the Water 7 Arc but rejoined during the Enies Lobby Arc.

Born into a family of archaeologists, Robin is the daughter of Nico Olvia. Robin ate the Hana Hana no Mi at a young age, giving her the power to reproduce her body parts (or her entire body) on any surface at will. As the sole survivor of the destroyed West Blue island Ohara, she is currently one of only two people in the world known to have the ability to read and decipher Poneglyphs, a skill which is considered forbidden and threatening to the World Government.

She gained a bounty of Beli79,000,000 at the age of 8 due to her ability to read poneglyphs after the destruction of Ohara. It later increased to Beli80,000,000 after the Straw Hats invaded Enies Lobby to rescue her and escape. After the Dressrosa Arc, it was increased to Beli130,000,000. Following the Raid on Onigashima, her bounty was increased to Beli930,000,000.

"Iron Man" Franky is the shipwright of the Straw Hat Pirates and one of the Senior Officers of the Straw Hat Grand Fleet. He is the crew's eighth member and the seventh to join, doing so at the end of the Post-Enies Lobby Arc.

Born "Cutty Flam", he chose to go by his nickname of "Franky" until eventually permanently discarding his true name per the request of Iceburg to hide his identity. Originally from the South Blue, Franky was abandoned by his family as a four-year-old, eventually making his way to Water 7. There, he came to be a member of Tom's Workers, until an incident resulted in his body being heavily damaged and requiring him to augment himself into a cyborg. Upon returning to Water 7, he became the leader of the Franky Family, a group of ship dismantlers and bounty hunters. Franky and his followers were originally enemies of the Straw Hats at the beginning of the Water 7 Arc, until circumstances forced them to become allies at the end of the same arc and the Enies Lobby Arc. 

He gained a bounty of Beli44,000,000 for his involvement at the Enies Lobby Incident. It later increased to Beli94,000,000 after the Dressrosa Arc. Following the Raid on Onigashima, his bounty was increased to Beli394,000,000.

"Soul King" Brook is the musician of the Straw Hat Pirates, one of their two swordsmen, and one of the Senior Officers of the Straw Hat Grand Fleet. He is the ninth member of the crew and the eighth to join, doing so at the end of the Thriller Bark Arc.

Brook ate the Yomi Yomi no Mi, which allowed him to return to life after death once. Brook eventually learned to tap deeper into the powers of his Devil Fruit, giving him significant control over his own soul and the souls of others.

Originally a member of the Rumbar Pirates, he died and was resurrected through the power of the Yomi Yomi no Mi. However, due to the amount of time it took for his soul to find his body, it was reduced to a skeleton, keeping only his afro intact. Brook drifted alone in the Florian Triangle for 50 years, eventually meeting Luffy and serving as the Straw Hats' ally during the Thriller Bark Arc before officially joining the crew. His dream is to reunite with his old friend, Laboon, at Reverse Mountain, where he resides with Crocus.

He first gained a bounty of Beli33,000,000 during his time as a member of the Rumbar Pirates. It later increased to Beli83,000,000 after the Dressrosa Arc. Following the Raid on Onigashima, his bounty was increased to Beli383,000,000.