Caspar Mathias Spoo (7 January 1837 – 17 March 1914) was a Luxembourgish industrialist and politician.
Spoo was born in Echternach in 1837. His parents were workers in the earthenware factory, and died early. He joined the civil service from a young age, to make a living for himself and his siblings. He gave up his position in the postal service in order to open the Société Duchscher Frères et Spoo with André Duchscher, his old friend. From 1886, he worked for two years as an accountant at the Dudelange foundry; he then struck out on his own in 1888 to open an ironmongery in Esch-Alzette with a workshop constructing ovens, cauldrons, etc.: the Maschinenfabrik Spoo & Co.
Additionally, he was politically active. He was elected to the communal council of Esch in 1893 and to the Chamber of Deputies in 1896. Along with Michel Welter, he was one of the first people to engage in modern election campaigning in Luxembourg, by drafting and publishing a manifesto and giving speeches. Politically, he belonged to the left-liberal middle-class. Influenced by André Duchscher, he campaigned for universal suffrage, progressive taxation and social security. He also called for the construction of an industrial school and a secondary school for girls in Esch, and demanded that the canton of Esch, whose economic and demographic importance had increased due to industrialisation, should receive more seats in the Chamber. His social campaigning, in the paternalistic tradition of the 19th century, earned him the nickname "Pappa Spoo".
He was married to Barbe Kiesel, and was the father of Armand Spoo. At his funeral in Esch, Michel Welter gave a eulogy, calling Spoo the "conscience of Luxembourgish socialism."
