I am the world's biggest chicken when it comes to rides that involve any type of heights. So the thought of having to tackle some of the rides at Walt Disney World terrified me. I highly suggest to get the most fun out of your Walt Disney World vacation that you try to push some of your fears and attempt rides that you wouldn't normally attempt but at that same time it is important to know what your limits are when it comes to rides. On our recent trip I rode rides that I wouldn't normally have rode due to heights, but there were also some rides I knew there was no way I could manage. This is where it important to be honest with yourself and know what you can handle. Also one great way to judge how terrifying a ride will be for you is to watch videos of rides on You Tube. You can judge pretty well how each ride will go from the videos. I did this for pretty much every ride before our trip, and it let me get a good idea of what the rides were going to be like.
Here are the Magic Kingdom rides that I think could possibly be an issue for you if you are afraid of heights.
Astro Orbiter - If you are afraid of heights just looking at Astro Orbiter will make you queasy. With Astro Orbiter you actually have to ride up an elevator to get onto the ride itself. Even my thrill ride loving kids found the height of this one scary so if you have a fear of heights this is definitely one you will want to skip.
The Barnstormer - The Barnstormer is considered a kids roller coaster in Fantasyland but this mild roller coaster moves fast. You never go upside down and the ride is over fast. If you want to give a roller coaster a try, this would be a great entry level roller coaster if you are afraid of heights. The good thing is that you can view the ride before getting on it so you can evaluate whether or not you think you can handle it.
Big Thunder Mountain Railroad - For those afraid of heights Big Thunder Mountain Railroad sounds like your worst nightmare. The good thing about Big Thunder Mountain Railroad is that you stay on a flat surface the entire time, and are never really "hanging" the way you would on a traditional roller coaster. There are a couple of climbs that might be a little tough if you are scared of heights.
Dumbo the Flying Elephant - This iconic ride does go up in the air and can be terrifying for someone scared of heights. For me I skipped this ride.
The Magic Carpets of Aladdin - Another ride that goes up in the air the way Dumbo the Flying Elephant does and that I skipped.
Peter Pan's Flight - This ride took me by surprise, as I wasn't expecting it to lift off the way it did. The ride is worth it because it is beautiful. I ended up riding it a second time. I highly suggest that you don't let your fear of heights hold you back from this ride. Just remind yourself that this is a ride where Disney magic makes it appear that you are actually much higher up than you really are. In reality you are just a few feet up off the ground and it is a slow moving ride. Unfortunately since this ride is indoors you can't scope it out to beforehand see how you think it will be for you.
Seven Dwarfs Mine Train - This ride is considered to be an "introductory" roller coaster of sorts. I personally chose to skip it because of my height issues but others who say they have a fear of heights have given this ride a shot without issues. One suggestion was to ride at night so that you really couldn't "see" how high you are. Like some of the other rides the majority of this ride takes place on the outside so you can get a good idea of what the ride will be like.
Space Mountain - I will admit I rode Space Mountain one time. I was eight and my step-mom convinced me to ride it with her. This ride terrified me! There are differing opinions on whether or not Space Mountain is good if you are afraid of heights. Some people feel that because the ride is dark and you can't "see" how high up you are that this ride is okay. The truth is that this ride does have big drops. The ride through videos of this ride aren't much help because they are dark. This is one you will have to judge for yourself, but my opinion is if you have a height issue as severe as mine you may want to skip it.
Splash Mountain - I really, really, really wanted to ride this ride with my kids but couldn't get up the courage to do it. I even tried riding Kali River Rapids in Animal Kingdom hoping that it would "prep" me to ride Splash Mountain but I just couldn't get up the nerve to do it. The majority of the ride is an indoor, smooth, slow moving ride but the end of the ride features a 52 1/2 foot drop! You can see the drop from the outside of the ride so it will give you a good idea of whether or not you can handle it. The drop does go quickly though if you decide you want to give it a try.
Swiss Family Treehouse - This is not a ride but a walk through attraction in Magic Kingdom. As you climb through the Swiss Family Robinson Treehouse you will be several stories up in the air. This is probably a good attraction to avoid if you are afraid of heights.
Tommorowland Transit Authority People Mover - The People Mover takes you on a ride tour of Tommorowland and you are up in the air. However, I have rode this ride several times and the height has never bothered me. I highly suggest that you give it a try even if you are afraid of heights.
This list may seem long but there are plenty of rides in the Magic Kingdom that you can still enjoy that involve no heights at all.