William Arvis "Dollar Bill" Blakley (November 17, 1898 – January 5, 1976) was an American politician and businessman from the state of Texas.

He served twice as an interim United States Senator, appointed by the Governor to fill a vacancy until his successor could be duly elected.

Blakley served with the United States Army in the First World War; he was admitted to the bar in 1933 and joined a law firm in Dallas, Texas.

In following years, his interests expanded into real estate, ranch land, banking, and insurance; by 1957, he was estimated to be worth $300 million.

Blakley, who had gained prominence in Texas politics for his business successes, was building a $125 million shopping center and a 1,000-room hotel in Dallas.

Pressured by the Democratic Party to cool tensions from the gubernatorial election, Blakley did not seek the remaining term as senator and served for fewer than four months, from January 15 to April 28, 1957.

After that, Texas law was changed to require a runoff between the two leading candidates in a special election if no one had a majority in the first round.

The Speaker of the U.S. House of Representatives, fellow Texan Sam Rayburn, backed Yarborough in the primary though he had supported Blakley's Senate appointment in 1957.