The Rialto is and has been for many centuries the financial and commercial centre of Venice. It is an area of the San Polo sestiere of Venice, also known for its markets and for the Rialto Bridge across the Grand Canal.

The area was settled by the ninth century, when a small area in the middle of the Realtine Islands either side of the Rio Businiacus was known as the Rivoaltus, the "high bank". Soon, the Businiacus became known as the Grand Canal, and the district became the Rialto, referring only to the area on the left bank.

The Rialto became an important district in 1097, when Venice's market moved there, and in the following century a boat bridge was set up across the Grand Canal providing access to it. This was soon replaced by the Rialto Bridge.