Leo Zimmermann was a farmer from the village of Todtmoos in Waldshut, Baden-Württemberg, Germany. Zimmermann's brothers Arnold and Edwin, both labourers, had left Germany for Québec, via Antwerp in 1911. Their intended final destination was Saskatoon in Canada and the unmarried Leo decided to make the journey to join them the following year.

He boarded Titanic in Southampton as a third class passenger and provided his destination as the home of his brother Edwin in Saskatoon.

He shared cabin E58 on F-Deck with Josef Arnold, Anton Kink, Vincenz Kink, Albert Wirz and a Bohemian man, probably Wenzel Linhart.

Leo perished in the disaster and his body, if recovered, was never identified. His brother Arnold was still living and working as a farmer in Saskatoon at the time of the 1916 census but no further information has come to light.