Jan Herman van Roijen (10 April 1905 – 16 March 1991) was a Dutch diplomat and politician.

He was the son of Jan Herman van Roijen Sr (1871–1933) and the American-born Albertina Taylor Winthrop (1871–1934), who married in May 1904.

[1] His maternal grandparents were banker Robert Winthrop and the former Kate Wilson Taylor (a daughter of Moses Taylor, a prominent railroad financier who served as president of National City Bank).

[1] Van Roijen's diplomatic career began in the 1930s when he joined the Dutch Ministry of Foreign Affairs in 1930 and was an attache in Washington for three years.

[2] He received an Honorary Doctor of Civil Law from The University of Toledo on June 8, 1957.