How to make a Horizontal List in SwiftUI?

I can wrap all my views inside a List

List {
   // contents
}

But this seems to be vertical scrolling. How do I make it horizontal?

You need to add .horizontal property to the scrollview. otherwise it won't scroll.

ScrollView (.horizontal, showsIndicators: false) {
     HStack {
         //contents
     }
}.frame(height: 100)

Update

ScrollView {
    LazyHStack {
         ForEach(arrayOfContent, id: \.id) { item in
              // content
         }
         .listStyle(.plain)
    }
}

Starting from iOS 14 beta1 & XCode 12 beta1 you will be able to wrap LazyHStack in a ScrollView to create a horizontal lazy list of items, i.e., each item will only be loaded on demand:

ScrollView(.horizontal) {
            LazyHStack {
                ForEach(0...50, id: \.self) { index in
                    Text(String(index))
                        .onAppear {
                            print(index)
                        }
                }
            }
        }