Christopher A. Alexander PC (born September 9, 1968) is a former Canadian diplomat and politician. A member of the Conservative Party, he represented the riding of Ajax—Pickering in the House of Commons of Canada from 2011 to 2015 and served as the minister of citizenship and immigration from 2013 to 2015. Alexander was the Canadian ambassador to Afghanistan from 2003 to 2005.

Alexander spent 18 years in the Canadian Foreign Service and served as Canada's first resident Ambassador to Afghanistan from 2003 to 2005. Following this, he served as a Deputy Special Representative of the United Nations Assistance Mission in Afghanistan until 2009. After winning his seat in the 2011 election, Alexander was appointed Parliamentary Secretary to the Minister of National Defence. On July 15, 2013, he was appointed Minister of Citizenship and Immigration. He ran for the leadership of the Conservative Party of Canada in 2017, placing 10th in a field of 14 candidates.

Alexander was born in Toronto, the son of Andrea Alexander, a high school teacher, and Bruce Alexander, a lawyer and assistant deputy minister in the Ontario government. His grandfather, Don Lough, was mayor of Huntsville, Ontario. After graduating from the University of Toronto Schools, Alexander earned a Bachelor of Arts in history and politics from McGill University in 1989 and a Master of Arts in politics, philosophy, and economics from Balliol College, Oxford in 1991. He studied at Université Laval for the first six months of 1989.

In 1991, Alexander joined the Canadian Foreign Service. He was posted to the Canadian embassy in Russia in 1993 as Third Secretary and Vice-Consul. In 1996, he returned to Ottawa to become an assistant to the Deputy Minister of Foreign Affairs. In 1997, he became Deputy Director (Russia) of the Eastern Europe Division responsible for political and trade relations. In 2002, he returned to the Canadian embassy in Moscow as Minister Counsellor (Political).

In 2003, Alexander applied for the position of Canadian ambassador in Kabul, Afghanistan. He was selected for the position and presented his credentials in August 2003, relieving resident chargé d'affaires a.i. Keith Fountain. From 2005 until mid-2009, he served as one of two Deputy Special Representatives of the Secretary-General (SRSG) of the United Nations in the United Nations Assistance Mission in Afghanistan (UNAMA).

Alexander's performance in diplomacy circles was widely lauded. He was described by various commenters as "sensitive to the Afghan culture, knowledgeable, persuasive, totally committed, and hardworking;" "perhaps one of the brightest and most capable diplomats that have come to Afghanistan over the past five years;" and "the best ambassador I've ever worked for." Major General David Fraser, commander of NATO forces in southern Afghanistan, referred to him simply as "an amazing man."

On April 12, 2010, CBC News revealed that Alexander, as a senior official working with the United Nations, alleged that Asadullah Khalid, the former governor of Kandahar Province in Afghanistan, had ordered the killing of five UN workers by bombing, presumably to protect his narcotics interests.

On December 12, 2019, The Globe and Mail published a lengthy opinion piece written by Alexander in which he stated that for most of his time in Afghanistan, he believed that Western strategy "was wrong" in that it did not focus on Pakistan's military support for the Taliban as the root cause of the conflict.