William Gustavus Conley (January 8, 1866 - October 21, 1940) was the 18th governor of West Virginia, serving from 1929 to 1933. Born near Kingwood in Preston County, Conley attended district schools and as a young man worked on the family farm, drove mules on railroad gangs, dug coal, and worked in quarries and sawmills to help support his sisters and widowed mother. He taught school from 1886 to 1891 and served as superintendent of Preston County schools from 1891 to 1893.

He earned a law degree from West Virginia University in 1893 and began practicing law in Parsons, Tucker County. While there Conley founded the Parsons Advocate newspaper in 1896 and acted as editor until 1903. A Republican, he became active in local politics as prosecuting attorney for Tucker County, a member of the Parsons city council from 1897 to 1899, and as mayor from 1901 to 1903. Returning to Kingwood, Conley continued his political involvement as city council member and mayor of that town from 1906 to 1908. Governor Dawson appointed Conley to an unexpired term as West Virginia attorney general in the spring of 1908, and in November he was elected to that office. He was narrowly defeated in the congressional race in West Virginia's second district in 1912, after which he practiced law in Charleston, representing corporate clients such as the Baltimore & Ohio and Pennsylvania railroads. Conley remained involved in Republican politics and pursued an interest in the coal industry as president of the West Virginia Eagle Coal Company and the Coalfield Fuel Company.

Conley defeated Democrat Alfred Taylor in the 1928 gubernatorial race by nearly 50,000 votes. His tenure as governor coincided with the darkest days of the Great Depression. More than 30,000 West Virginia coal jobs disappeared between 1929 and 1932, 100 banks failed, and farmers were devastated by severe droughts and the collapse of farm prices. Equal disasters plagued manufacturing in the state. Faced with these crises, Conley diverged from his intrinsic suspicion of what he referred to as government paternalism and promoted state fiscal initiatives and direct federal relief to combat the effects of the Depression.

Democratic victories in state elections in 1930, resulting in the first Democratic legislative majority in West Virginia since 1923, made the 64-year-old Conley a virtual lame duck halfway through his term. Realizing that he had no political future after the governorship and disturbed at the specter of unemployed West Virginia veterans marching on Washington in the summer of 1932, Conley altered his ideological aversion to what he called the "government nursing bottle" and carried out a moderately activist relief agenda. He shifted some county road funds into direct relief for the hungry and unemployed and issued state bonds for road construction in order to stimulate employment. He also advocated "sin" and luxury taxes to fund expanded state unemployment relief. Many of Conley's relief proposals, however, failed to win support from the Democratic majority.

Republicans and Democrats alike sought credit for implementation of the most important legislation of Conley's term, the Tax Limitation Amendment, which emerged from a special session called by the governor in the summer of 1932. Voters in the 1932 election approved the popular measure designed to provide universal property tax relief, and it took effect after Conley left office. The populist appeal of the amendment proved illusory, as low property tax ceilings forced the state to assume school financing and road maintenance services that previously had been the responsibility of the counties. Subsequent conservative Democratic administrations addressed revenue shortfalls created by the amendment with regressive taxation on such items as food and medicines.

After his term ended, Conley returned to private law practice in Charleston. He was head of the firm of Conley, Thompson, and Neff when he died at age 74.