While the other two current answers here are correct, I believe that they do the OP a disservice by stating that the matter is simple and not complicated. At least for me, the timing of Death Ward vs. massive damage introduces a non-intuitive level of complication.
Death Ward will save you
but there may be a complicated timing issue
You specified that you are casting Death Ward on yourself, so the least maximum hp you could have would be as a 7th level cleric; a higher level cleric, or any paladin, would have more hp.
Realistically as a cleric you likely have a +2 hp / level from Con at seventh level, so around 52 hp (more with a higher Con or a racial bonus, fewer with a lower Con).
The average of 20d6 (maximum fall damage from a great height) is 70hp, but within the distribution you could receive more than 104 points of damage. Or, you could start the fall wounded, or with a lower hp maximum than 52. The point is that it is entirely possible for the fall damage to exceed the sum of (your current hp + your maximum hp).
Let's say you are at 52 hp and you take 70hp of damage from the fall. You can't be at negative hp, so you would go to zero, but then the death ward is triggered and you go to 1hp instead. Death Ward has saved you! You are conscious, no death saves are needed, end of story. This is the simple case.
But suppose you are at 52hp and the fall damage is 104hp or more. Now, the fall damage would take you to 0hp, but you have to worry about two triggers - both the death ward, and the "massive damage" rule which states
Massive damage can kill you instantly. When damage reduces you to 0 hit points and there is damage remaining, you die if the remaining damage equals or exceeds your hit point maximum.
Since you were at 52 hp when you took 104 hp of damage, you would be at 0hp with 52hp of damage "remaining" - this could trigger instant death by massive damage. The death ward would not protect you from this death, because it only protects from instant deaths that kill you without doing damage:
If the spell is still in effect when the target is subjected to an effect that would kill it instantaneously without dealing damage, that effect is instead negated against the target, and the spell ends.
However, the death ward could protect you by making sure your hp are never at 0, since the trigger for the massive damage - instant death rule is "when damage reduces you to 0hp".
Thus, the question becomes one of what happens first - when your hit points become 0 from the fall, does the death ward reset them to 1 and thus protect you from death by massive damage before it can trigger, or does the massive damage kill you in a way that the death ward cannot prevent before your hp are reset?
As it turns out, death ward goes first because of the way it is worded. As this answer to this question explains, the order of precedence is such that "would be" effects trigger before "reduces" effects. Death ward specifically says
The first time the target would drop to 0 hit points as a result of taking damage, the target instead drops to 1 hit point, and the spell ends.
while the massive damage rule says
When damage reduces you to 0 hit points and there is damage remaining
Because the death ward triggers first, you are never actually at 0 hp, you become 1hp after the fall but before the massive damage rule can apply. Since you are never at 0hp, massive damage cannot trigger.
As the other answers have said, death ward will protect you - but unlike them, I believe it is in a complicated way that depends on the timing of effects.
