The Senate Republican Conference is the formal organization of the Republican Senators in the United States Senate, who currently number 49. Over the last century, the mission of the conference has expanded and been shaped as a means of informing the media of the opinions and activities of Senate Republicans. Today the Senate Republican Conference assists Republican Senators by providing a full range of communications services including graphics, radio, television, and the Internet. Its current Chairman is Senator John Barrasso, and its Vice Chairwoman is currently Senator Shelley Moore Capito.

William Boyd Allison was an American politician. An early leader of the Iowa Republican Party, he represented northeastern Iowa in the United States House of Representatives before representing his state in the United States Senate. By the 1890s, Allison had become one of the "big four" key Republicans who largely controlled the Senate, along with Orville H. Platt of Connecticut, John Coit Spooner of Wisconsin and Nelson W. Aldrich of Rhode Island.