Fredrik Reinfeldt, Swedish soldier and politician, 42nd Prime Minister of Sweden
John Fredrik Reinfeldt (pronounced [ˈfrěːdrɪk ˈrâjnːfɛlt] (listen); born 4 August 1965) is a Swedish economist, lecturer, and former politician who was Prime Minister of Sweden from 2006 to 2014, and chairman of the liberal conservative Moderate Party from 2003 to 2015. He was the last rotating President of the European Council in 2009.

A native of Stockholm County, Reinfeldt joined the Moderate Youth League in 1983, and by 1992 had risen to the rank of chairman, a position he held until 1995. He served as Member of Parliament from 1991 to 2014, representing his home constituency. Reinfeldt was elected party leader on 25 October 2003, succeeding Bo Lundgren. Under his leadership, the Moderate Party has transformed its policies and oriented itself closer to the political centre, branding itself "the New Moderates" (Swedish: Nya moderaterna). In 2010, under Reinfeldt's leadership, the Moderate Party got its highest share of the vote since the introduction of universal suffrage in 1921.

Following the 2006 general election, Reinfeldt was elected Prime Minister on 6 October. Along with the three other political parties in the centre-right Alliance for Sweden, Reinfeldt presided over a coalition government with the support of a narrow majority in parliament. At the age of 41, he was the third-youngest person to become Prime Minister of Sweden.

Reinfeldt's first term in office was marked by the late-2000s financial crisis and recession. His popularity fell until the economy of Sweden emerged as one of the strongest in Europe; this brought a resurgence of support for him, resulting in his government's re-election in 2010. However, Reinfeldt's second government was reduced to a minority government, owing to the rise of Sweden Democrats; but he remained in power as the first centre-right Prime Minister since the Swedish-Norwegian Union to be re-elected ..

His premiership was characterised by "Arbetslinjen" (English: Working line), a focus on getting more people into the workforce, and by management of the late-2000s financial crisis and recession which resulted in one of the world's strongest public finances and top rankings in climate and health care.

He is the longest-serving non-Social Democratic Prime Minister since Erik Gustaf Boström's first spell in office between 1891 and 1900. After his defeat in the 2014 election Reinfeldt announced that he would step down from leading the party, which he did on 10 January 2015.