Is it normal to fall in love with someone you haven't met in person? P.s. I've been speaking to this person for over a year.

It is absolutely normal. But it is not common.

As citizen of this generation, i have witnessed both sides of the story. You haven't mention what the connection is based on, but unconsciously i assume it would be internet. As the internet age arrived the world experienced this so i'd call "virtual sights of love" and to many it can not make sense by any means. But to some, they found their beloved partner this way. I have witnessed both danger and peace, disaster endings and happy endings following this frame.

In my perspective, life is not physical, we are all emotions. Without our feelings, we are nothing. Thus i believe in such type of loves. To me, it only depends on individuals. If have faith and know how to manage. It can have a happy ending. But this is something i can not recommend to anyone to follow. There are risks, there's possibilities, it could end up anyhow if the person not be aware of how to control and manage the relation. The side effects can be harmful. So it is normal. But you can't find many people to agree with you on going down to this path.

I've met people only on the internet (some of them are on this site)  for whom I feel very genuine affection. You can build a friendship on the Internet the same way we used to do with pen pals.

But love? Well, yes, but meeting face to face might be a let down. Never forget that the Internet is the home of illusion. A very clever songwriter, Joe Darion, once wrote, "A man with moonlight in his hands has nothing there at all."

Been there. Done that.

I would think it is more appropriate to say you have fallen in love with the idea of them. Until you meet them, you really don't know themor what they are really like

Without meeting someone face to face, you have not had the benefit of interpreting them other than by what they have told you about themselves. 

All you know about them is what they have told you .. You don't know their family nor their friends, nor how they conduct themselves around others or in the real world. You have no way of determining or supporting evidence of anything they've told you as actual truth.

Trusting someone takes a leap of faith even when substantiated with all of these elements.  There is always a level of risk involved. Trusting someone without substantiation is even more risky.

You have not fallen in love who they are, you have fallen in love with who you 'think' they are. 

Normal, yes.

Common, no.

But romantic love eventually will involve their physical presence.

In my experience, our virtual "counterparts" are very different than our real selves.