Where to get Fly in Pokemon Red/Blue/Yellow
As well as letting you fast travel around the map, Fly is a useful 2-turn attacking move in Pokemon Red/Blue/Yellow!
Pokemon is one of the few game franchises where fast-travel actually makes sense. Rather than teleporting instantly to where you need to go faster than you can say "ludonarrative dissonance", your character in Pokemon Red and Blue simply hops on the back of their flying Pokemon and soars off into the sunset.
But while this vital ability is something every Pokemon trainer should seek out, it's actually incredibly easy to miss, hidden as it is behind a completely optional pathway - on a path that is itself optional.
Here's where to grab the Fly HM for yourself!
Pokemon Red/Blue/Yellow Fly location
To get Fly, make your way to Celadon City by heading left from Lavender Town after traversing Rock Tunnel. When you reach Celadon, continue all the way left into the top-left corner of the city, past the department store.
The path here is called Route 16, and about half way down it - before the Snorlax - there's a tree you can use Cut on. Cut down the tree, then go up and to the left. Through the other side of the gate, which you can pass without giving the guard a drink, speak to the woman in the hidden house.
If you promise not to reveal the location of her hideaway, to whom I'm not sure, she'll hand over the Fly HM as a reward.
You need to have defeated Lt. Surge to use Fly outside of battle, but that shouldn't be an issue by the time you reach this point in your adventure.
Which Pokemon can learn fly in Pokemon Red, Blue and Yellow?
That might seem like a simple question, but there are some edge cases to consider. First, most Flying-type Pokemon like the Pidgey and Spearow families can learn Fly, but that also includes Doduo and Dodrio, which are canonically flightless birds without wings.
Despite being far too small to carry the weight of a human, Farfetch'd can learn Fly too, and is a great candidate since it can learn Cut as well.
However, Pokemon that can canonically levitate, including Ghost-types like Ghastly and Haunter and Psychic-types like Kadabra and Mewtwo, cannot learn Fly.