Is The Catholic Church The Largest Single Organized Religion?

Wikipedia says: The Catholic Church, is the world’s largest Christian church, representing over half of all Christians and one-sixth of the world’s population.
With the fact that Christianity is the dominant Earthly religion in mind, the answer to your question is a solid, resounding yes.
Not only do Catholics represent the largest organized religion, but the largest religion, period. Not necessarily the fastest growing, however.

They are certainly the greatest organized con and the most successful con in the history of the world!!
The Roman Emperor Constantine produced the bible and he was a pagan not god!!! He also organized Christianity into the Holly Roman Catholic Church!! Not in Israel or any of the countries of supposed origin but entirely Italian!!
Not one word of it is contemporary with the period and was not written until many years after the period the story is set in!!
What a wonder full disinformation and deception campaign he waged against his Christian enemies – so good in fact that Christians are still following the deception to this day!!!

Among the Christians, yes. Last I heard, there were about 51 million Catholics in the USA alone (I used to be one of them before I came to my senses). It must make the bible fundies shudder in their shoes. Not to mention the amount of wealth the church controls.
And the world should probably be grateful the Muslims aren’t that organized, considering their designs on world domination.

Catholicism is if you think that the Philippines is the centre of the universe, In much of the world (excluding South America) it is declining in population share. Even in Italy and France, formerly Catholic nations, its dwindling. North America certainly not.

The single largest denomination now is Sunni Islam. Roman Catholic Church has receded to second position.

Yes – the greatest waste of human life and human energy in the world.

Sad, but true!

Yes.