Johannes Aleidis (Johan) Ringers CBE (Alkmaar, 2 January 1885 – The Hague, 6 May 1965) was a Dutch hydraulic engineer and politician.

[1] After completing his education at the Hogere Burgerschool in Alkmaar, Ringers studied at the Technical University of Delft, where he obtained his diploma in Civil Engineering in 1906.

[3] After completing the IJmuiden project, Ringers became involved with the Zuiderzee Works as chief director of the Maatschappij tot Uitvoering van Zuiderzeewerken on 1 January 1927.

Before the outbreak of war, the Dutch Minister of Defence had ordered measures to prevent enemy action from damaging hydraulic engineering structures.

[1][6] On Ringers' advice, decisions were made within a few days to bring all areas of land were buildings in Rotterdam had been destroyed by German bombing into state ownership, thereby allowing immediate disposal of rubble and commencement of reconstruction.

[7] In recognition of his efforts, Rotterdam honoured him in 1963 as the "father of reconstruction" with a plaque in the office of municipal public works, the Stadstimmerhuis.

His arrest was part of mass detentions ordered by J. Schreieder, head of Referat IV E of the Sicherheitspolizei, targeting the Vorrink Group and the National Committee in the context of the Englandspiel, a German counterintelligence operation.

[1][6] Ringers spent about seven and a half months in prison in Scheveningen, where he continued some of his work, including designing a plan for heating the city of Rotterdam using primitive methods.

[1] For his exceptional contributions to the reconstruction, Ringers was awarded the Van Oldenbarnevelt Medal in 1963, the highest municipal distinction of the city of Rotterdam.

However, he disagreed with the policy of the Netherlands towards Indonesia, specifically the Linggadjati Agreement, leading him to tender his resignation on 30 October 1946, which was accepted on 15 November 1946.