The Order of the Phoenix were among the most important and impactful characters in the Harry Potter franchise, and although not everybody showed up for the final battle against Voldemort, the outcome of both Wizarding Wars would’ve been very different without them. The original Order was founded by Albus Dumbledore and his closest friends when Voldemort first rose to power long before the events of the movies even take place. While the roster kept changing throughout the years, the Order was always there to protect Harry and fight the good fight.
The Battle of Hogwarts saw Voldemort finally march on the prestigious Wizarding school in a failed attempt to kill Harry once and for all. There were plenty of casualties (including some of Harry’s closest friends and most loyal allies), but the Order ultimately bought Harry enough time to destroy the Horcruxes and kill the Dark Lord. Although many Battle of Hogwarts were left out of the Harry Potter movies, the roster of characters remained pretty much the same - which is hugely important, because certain ’ absence from the battle speaks volumes about their character.
Rubeus Hagrid
Rubeus Hagrid has always been loyal to Dumbledore, and in the fallout of his close friend’s death, he continued to fight for what Albus believed in. He fought on the front lines of the Battle of Hogwarts, even though he was quickly overcome by the Death Eaters and forced to deliver Harry’s 'dead body' to the gates of the school. Hagrid was never the most talented wizard in the Order of the Phoenix, but his dedication and devotion to the cause made him a valuable asset. Also, it’s likely that Harry never would’ve even made it to the Battle of Hogwarts without Hagrid’s protection and advice over the years.
Fleur Delacour
Although she wasn't introduced until Harry Potter and the Goblet of Fire, Fleur Delacour quickly became an integral part of the gang’s fight against Voldemort. She’s one of the younger of the Order, but her associations with the Weasley family quickly put her in the middle of the conflict. After falling in love with Bill Weasley, Fleur dedicated herself to fighting against the Death Eaters and even risked her life at the Battle of Hogwarts. As she displayed in the Triwizard Tournament, she’s very talented with magic - so her assistance would’ve been a huge help.
Bill Weasley
As the oldest child of Molly and Arthur, Bill Weasley felt a huge responsibility to protect his family and represent them in the battle against Voldemort. He was inspired by his parent’s courage and bravery during the first Wizarding War, and his character clearly represents how their skills and convictions have been ed down to the next generation. During his time at Hogwarts, he’d been both a Prefect and Head Boy, so he clearly knows the theory behind his combat and the Battle of Hogwarts allowed him to prove his physical abilities too.
Charlie Weasley
Although Charlie is often forgotten among the Weasley siblings, his importance in the Battle of Hogwarts shouldn’t be overlooked. Though he didn’t fight on the front lines like many of his peers, he was the one who brought the reinforcements that would hold Voldemort back from the grounds while Harry and his friends devised a way to defeat him. The outcome of the battle would’ve been very different without Charlie’s help, and that instantly makes him one of the Order’s most invaluable . Like his brothers, Charlie risked his life on that day to ensure that Harry had enough time and supplies to bring down Voldemort once and for all.
Remus Lupin
Although the Harry Potter movies made Peter Pettigrew’s death more ambiguous, it’s clear in the books that when the Battle of Hogwarts rolls around, Remus Lupin is the last surviving member of the Marauders. The former Dark Arts professor serves as Harry’s final connection to the life of his parents, and although he’s ultimately killed at the hands of Death Eater, Antonin Dolohov, the fact that he fought in the first place just proves how much he’s invested in the cause. He spent his whole life fighting for the Potters, right until his last breath.
Minerva McGonagall
The Harry Potter movies never really portrayed McGonagall as a powerful fighter, but in that final battle, she was ready to give her life to protect Hogwarts from more dark forces. Despite the latter’s clear power advantage over her, she was among the first people to stand up to Severus Snape when he was instated as the school’s Heaster. McGonagall is an incredibly wise character, and while she wasn't as prepared to fight alongside the Order during the Second Wizarding War, she stood her ground when her school needed her.
Kingsley Shacklebolt
Although his role in the movies is only minor, Kingsley Shacklebolt is actually one of the Order's most powerful and formidable fighters. His talent with a wand is practically unmatched, and thanks to the many years he’s spent working as an Auror, he knows exactly how to handle himself in combat. Without him holding the Death Eaters back at the school’s gates, they would’ve probably breached the shield much earlier and Harry’s chances of victory would’ve been much lower. Kingsley Shacklebolt was one of the few Order of the Phoenix that actually survived the events of the books, later becoming Minister for Magic and rebuilding the Wizarding World.
Nymphadora Tonks
Tonks is an incredibly important character in the Harry Potter franchise, not only because of her relationship with Remus Lupin, but also because of her shared lineage with the Lestrange and Malfoy families. That made the Battle of Hogwarts extremely personal for her, and the fact that she chose to directly fight against her aunts, Bellatrix and Narcissus, proves just how loyal she was to the Order’s cause. Despite ultimately being killed alongside Remus, she was still a valuable member of the resistance and brought down several powerful Death Eaters on her way out.
Molly & Arthur Weasley
The Weasley siblings were all very powerful by the end of the Harry Potter franchise, but their parents often go underappreciated for their role in the defeat of Lord Voldemort. Not only were Molly and Arthur two of the founding of the Order of the Phoenix, but they were also the first to return when Voldemort made his comeback. They didn’t fight in every battle, but they were always there to and protect their friends whenever necessary. Molly was particularly useful in the Battle of Hogwarts, as she killed Voldemort’s closest follower, Bellatrix Lestrange. Without bringing her down, the battle could’ve definitely gone a different way.
Aberforth Dumbledore
Aberforth Dumbledore played a crucial role in ensuring that Harry’s arrival at the school went unnoticed, and, although he didn’t actually fight in the battle (at least in the movies), there’s no way Harry could’ve won without the element of surprise that Aberforth offered him. Voledmort and Dumbledore had a clear rivalry that ultimately resulted in the latter’s death, but his brother Aberforth was able to avenge him by risking his own safety and protecting Harry throughout The Deathly Hallows. He’s the unsung hero of the Battle of Hogwarts, even if his name isn’t often mentioned among the victors.
