Leopold was married to Princess Bertha of Hesse-Philippsthal-Barchfeld (1874–1919) on 16 August 1901 in Rotenburg. They had five children.
Ernst, Hereditary Prince of Lippe (1902–1987) married first (1924) Charlotte Ricken (1900–1974). After divorcing in 1934 he married secondly (1937) Herta-Elise Weiland (1911–1970)
Prince Leopold Bernhard of Lippe (1904–1965)
Princess Karoline of Lippe (1905–2001) married (1932) Count Hans von Kanitz (1893–1968)
Prince Chlodwig of Lippe (1909–2000) married (1940) Veronika Holl (1915–2007)
Princess Sieglinde of Lippe (1915–2008) married (1942) Friedrich Carl Heldman (1904–1977)
He was married secondly to Princess Anna of Ysenburg and Büdingen (1886–1980) on 26 April 1922 at Büdingen. From this marriage he had one son.
Armin, Prince of Lippe (1924–2015) married Traute Becker in 1953. Their only son is:
Stephan, Prince of Lippe, born 1959, married Countess Maria of Solms-Laubach in 1994