Johan Herbert Westermark (30 August 1891 – 29 October 1981) was a Swedish physician.

[2] Westermark received a Licentiate of Medicine degree in Stockholm in 1918 and then worked as an assistant physician (underläkare) at Karlskrona Hospital in 1919, aman at the obstetrics clinic at Allmänna BB in Stockholm in 1921.

[2] Westermark was a member of the board of the Swedish Medical Society (Svenska läkaresällskapets nämnd) from 1930 to 1955 and one of the principals for the Oscar II Jubilee Fund from 1937.

Westermark wrote about personal history, naval medicine, obstetrics and gynecology.

He was a crew member of the Swedish boat Sans Atout, which won the silver medal in the 8 metre class.