Can groom's dad be the best man?

There is no legal or traditional rule that says the best man cannot be the groom's dad. In fact, it can be a lovely choice. Your dad knows you well, will be proud to stand with you, and may give a heartfelt speech. He can also help with practical tasks, like holding the rings, making sure the groom is calm, and keeping an eye on the timeline. The only thing to consider is the speech. If your dad is the best man, he will usually give the best man's speech, which may feel different from a father-of-the-groom speech. You can decide together how to handle that. Some dads prefer to do both, others just one. Also think about whether your dad is comfortable with the more social duties, like organising the stag do or coordinating ushers. If he is not, you can share those tasks with a friend or another family member. The title is flexible. What matters is that the person in the role is willing and able to support you. If your dad is that person, go ahead. It will mean a lot to him and to you.