Social Democratic Party (Luxembourg)

Infobox_Political_party
name_english = Social Democratic Party
name_native = Parti Social Démocrate
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president = Henry Cravatte (1971 – 1980)
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foundation = 2 May 1970
dissolution = 1984
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ideology = Social democracy
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footnotes =The Social Democratic Party ( _lb. Sozialdemokratesch Partei, _fr. Parti Social Démocrate, _de. Sozialdemokratische Partei), abbreviated to SDP, was a social democratic political party in Luxembourg between 1970 and 1984. It was a splinter from the centrist tendency within the Luxembourg Socialist Workers' Party (LSAP).

The President of the party was Henry Cravatte, who had previously been the President of the LSAP between 1959 and 1970. Other key members include Albert Bousser and Astrid Lulling.

The party competed in the 1974 election, taking 9.2% of the vote and winning five seats, to draw level with the Communist Party, which had been the long-held fourth party in Luxembourgian politics. In 1979, the SDP lost three of their seats to a resurgent Christian Social People's Party (CSV). In the European election held on the same day, the SDP failed to win a seat, but did beat the Communist Party into fifth place.

Before it fought another election, the party disbanded, in 1984. Some of its members, including Cravatte, returned to the LSAP, whilst others, such as Lulling, joined the CSV, thereby completing their political metamorphosis from left to right.