Ralph Philip Klein OC AOE (November 1, 1942 – March 29, 2013) was a Canadian politician and journalist who served as the 12th premier of Alberta and leader of the Progressive Conservative Association of Alberta from 1992 until his retirement in 2006. Klein also served as the 32nd mayor of Calgary from 1980 to 1989.

Ralph was born and mostly grew up in Calgary, Alberta. After dropping out of High School in grade 11, Klein joined the Royal Canadian Air Force reserves for one year and then attended the Calgary Business College. Klein later worked as a teacher and principal at the Calgary Business College, and later public relations with non-profits. After that, Klein became a prominent local journalist in Calgary where he reported on the challenges of the working class, social outcasts and First Nations, endearing himself to those groups. In 1980, Klein turned his attention to politics and as an underdog was elected Mayor of Calgary, where he oversaw the boom and bust of the oil industry in the 1980s, expansion of the CTrain, and the 1988 Winter Olympic Games. Klein resigned as Mayor in 1989 and turned his attention to provincial politics where he served as Environment Minister in the Cabinet of Don Getty for four years.

In 1992, Klein was elected as leader of the Progressive Conservative Association of Alberta and went on to lead the party to a majority government in the 1993 Alberta general election; Klein continued the Progressive Conservative dynasty and won three more majority governments afterwards. Klein's informal style endeared him to Albertans early in his term, and his political longevity and centralized management style earned him the nickname "King Ralph". As premier, Klein oversaw a short period of drastic cuts to the public service and privatization of government services; this fiscal strategy ended in the late 1990s as rising oil and gas prices increased provincial tax revenues resulting in spending increases and paying down of the provincial government debt. Klein's 14-year-long tenure as premier ended when the Alberta Progressive Conservatives' new leader, Ed Stelmach, assumed office on December 14, 2006.

Klein was born in Calgary, to Philip Andrew Klein (1917–2014) and Florence Jeanette Harper (1924–2004). His paternal grandparents were immigrants, from Germany and England, respectively. His father, Phil, was born in Rocky Mountain House, Alberta, grew up poor and rode the rails during the Great Depression in search of work. In the early 1940s he married Florence Harper, a waitress, and lived in her parents' basement in Calgary while trying to make ends meet working in construction. Ralph Klein's parents separated when he was five or six years old and he spent time living with his maternal grandparents in the Calgary's north end, and Rocky Mountain House with his mother. After separating from his mother, Klein's father worked as a professional wrestler in the Alberta circuit for most of the 1950s using the name Phil "The Killer" Klein and later became a businessman.

Ralph Klein grew up in a working-class part of Calgary and dropped out of high school in grade 11, joined the Royal Canadian Air Force reserves, then completed high school later in life. Klein's time in the Air Force was limited, returning home a year later shortly after his 18th birthday. Klein attended Calgary Business College studying accounting and business administration, and later served as a teacher and principal of the college. He later studied at Athabasca University. Following his role at the Calgary Business College, Klein took a position as a public relations official at the Southern Alberta district of the Red Cross and United Way's offices in Calgary from 1963 to 1969.

Klein married Hilda May Hepner on April 29, 1961. They met at Portage-la-Prairie while Klein was training with the Air Force. As two strong willed individuals there were many difficulties in maintaining their relationship, and after several separations in the late-1960s and early-1970s, Klein and Hilda formally divorced on March 29, 1972, with adultery cited as the grounds for divorce. Hilda received custody of their two children. Klein remarried three months after his divorce to the Victoria-born Colleen Evelyn Hamilton, a single-mother with two children working as an accounting clerk with Imperial Oil and as a bartender by night. They were married in Colleen's mother's basement by Reverend Robert A. Simpson, and together Ralph and Colleen had one child.

Klein rose to public prominence in Calgary as a radio and television personality between 1969 and 1980. He was the Senior Civic Affairs reporter with CFCN-TV and CFCN radio. Klein built a reputation for thorough reporting and gritty, street-wise "down and dirty" reporter who could see through rhetoric. Klein's reporting style left him ostracized from the journalist community and provoked jealousy amongst the CFCN news group. Klein routinely skipped morning assignment meetings, rarely checked in, yet still would still appear in the afternoon with a new story. During his early career Klein became a staple patron of the St. Louis Hotel bar in Calgary's East Village, an area of synonymous with urban decay in the city.

Klein's early civic affairs beat revolved around following newly elected anti-establishment Mayor Rod Sykes. The relationship between the Mayor Sykes and Klein could be described as fickle, Klein alerted the Mayor to a Calgary Police Service's cannabis bust involving the Mayor's 13-year-old son which Klein believed would involve planting the drugs on the minor. Klein also alerted Sykes about a Canadian Broadcasting Corporation story on a proposed convention centre benefiting from city sources, which Sykes was able to temporarily delay, although Klein's reasons were somewhat selfish as the CBC story would have been released before Klein's story on the topic. Klein's story The Marriage later resulted in invasion of privacy charges pressed against Klein and CFCN over the leak of a meeting recordings, the charges were subsequently thrown out of court.