The worlds oldest living organism is 4,842 years old, and in hiding.

A Great Basin Bristlecone pine tree growing high in the White Mountains, named Methuselah is the world's oldest known living non-clonal organism. "Methuselah" was 4,789 years old when sampled in 1957, with an estimated germination date of 2832 BCE. The tree grows at 9,500–9,800 ft above sea level in the "Methuselah Grove" in the Ancient Bristlecone Pine Forest within the Inyo National Forest of Eastern California, but Methuselah's exact location is undisclosed to protect it  against vandalism.

http://en.wikipedia.org/wiki/Methuselah_(tree)