Center content in scroll view

You can use android:fillViewport="true" to center the content. Something like this:

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fillViewport="true">
        <!-- content -->
</ScrollView>

You should use an external horizontal LinearLayout. It's working for me in the same situation.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:orientation="horizontal" >
    <ScrollView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical" >
        <LinearLayout
                android:orientation="vertical"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:gravity="center_horizontal" >
            <TextView
                    android:text="@string/your_text"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
        </LinearLayout>
    </ScrollView>
</LinearLayout>