Neville could be a fellow professor. He was great at Herbology, so he'd be teaching that subject. He and Harry would support each other, and Neville could offer Harry advice on dealing with difficult students, as he had his own journey of growing from a shy student to a confident wizard. Harry would look up to Neville for his knowledge in Herbology and his kind - hearted approach to teaching.
Ron could also be there. Maybe he's the keeper of the Gryffindor Quidditch team still, but also helps out with some practical magic lessons. He could teach students about the magical creatures he encountered during his travels, like how to handle a Hippogriff properly. He and Harry would often joke around in the staff room, reminiscing about their school days.
Hermione would be a likely colleague. She's extremely intelligent and could be teaching a subject like Transfiguration or Ancient Runes. She would often share her vast knowledge with Harry and they could collaborate on projects for the students. Another could be Neville. He could be the Herbology professor. Given his own experiences with plants, especially the Venomous Tentacula, he would be great at teaching students how to handle dangerous plants safely.
Hermione would be a likely colleague. Given her thirst for knowledge and academic excellence, she might be teaching a subject like Ancient Runes or Arithmancy. They could often collaborate on projects related to the overall betterment of Hogwarts' curriculum.
Hermione would be a likely colleague. She's highly intelligent and could be teaching a subject like Ancient Runes or Arithmancy. Ron could also be there, perhaps as a flying instructor or teaching something related to magical creatures. Neville might be a Herbology professor, given his love and talent for that subject. Luna could be teaching something really unique, like the study of magical creatures that are often overlooked or misunderstood.
Perhaps Harry becomes a professor of Transfiguration. He could introduce new spells and techniques he learned during his adventures. Since he was so good at it during his school days, he would be able to pass on his knowledge and also inspire students to be creative with their transfigurations. He might even have a special project where students try to transfigure something really complex, like a whole building, which he guides them through step by step.
Hermione would surely be there. She might be a fellow professor, teaching a subject like Transfiguration or Ancient Runes. She could be Harry's confidante and help him with academic matters at Hogwarts. Also, Ron could make an appearance, perhaps as a visiting lecturer from time to time, sharing his knowledge of wizarding chess and other aspects of wizard culture.
One possible plot could be that Harry, after all his adventures, decides to return to Hogwarts to share his knowledge. He starts as an assistant professor, perhaps in Defense Against the Dark Arts. He uses his real - life experiences to make the classes exciting and relevant. His students look up to him, and he has to deal with some of the traditional Hogwarts politics among the staff.
Harry could also be a great Quidditch coach. He was an excellent Quidditch player himself. He would be able to train students in the skills of flying, teamwork, and strategy. He could pass on his love for the sport and perhaps even lead the school team to many victories. He would know how to spot potential in young players and help them develop their talents.
Perhaps Harry would try to make the DADA classroom a more inclusive and safe space. He had faced so much discrimination and danger himself when he was a student. So he would ensure that no student, whether they are Muggle - born or pure - blood, would feel left out or threatened in his class. He could also use his Gryffindor courage to inspire students to stand up against any form of dark arts or bullying.
Well, he might bring some major changes to Hogwarts. For example, he could reform the school rules to be more fair for all students, especially those from different houses. He might also use his new position to better protect the school from dark forces. Maybe he would start new magical studies programs that were previously overlooked.
It could be Professor Snape. Despite his often - cold exterior towards Harry, in a fanfiction scenario, there could be a moment of unexpected connection. Maybe Harry is injured in a potions accident and Snape, in a rare moment of compassion, has Harry sit in his lap while he administers a healing potion.