Conrad Carel Käyser (5 November 1876 – 26 April 1939) was a Dutch naval officer, explorer and mountaineer.

[1] He pursued a regular study for naval officers and had subsequent promotions in his career by the Royal Netherlands Navy.

After his return and the signing of the border demarcation protocols with England and Brazil he stayed in Paramaribo for some time until his departure to the Netherlands on 24 February 1939.

[3] Shortly after his arrival he had a conversation with minister Charles Welter on 26 April 1939 at the office in the Ministry of the Colonies in The Hague.

There, at the age of 62, Käyser suffered a sudden heart attack and medical assistance was promptly summoned in vain.