Religious organizations are not generally bound by the same financial reporting requirements as other entities, but the Catholic Church is very likely to be the wealthiest single religious organization on Earth. The Economist estimates that annual expenditures of the Catholic Church in the United States alone exceed $170 billion.
In addition to the 12-figure annual expenditures in just one country, the Vatican operates as a sovereign state with the power to levy taxes and own property. The Church's holdings include real estate, a substantial investment portfolio and works of art so rare as to be essentially priceless. The Vatican also operates a bank that has unknown deposits and assets.