No. The world's largest lake is the salty Caspian Sea at 143,200 square miles (370,886 km2) <http://geography.about.com/library/faq/blqzlargelake.htm>.
Close but no cigar.
The Largest Lakes by Surface Area are.
1. Caspian Sea - Asia - 371,000 sq km (143,000 sq mi)
2. Lake Superior - North America - 82,100 sq km (31,698 sq mi)
And the...