Willy "Wil" Hamerslag, often only referred to only by her surname Hamerslag (born 1900s) was a Dutch athletics competitor in the 1920s, specialized in the high jump and long jump. She was a member of Hygiëa, The Hague.

Hamerslag won multiple medals at national championships. She became 1925 national champion in the long jump with 4.885 metres. At the same championships she finished second in the athletics’ triathlon and third in the high jump.^[1]

In 1927 she became the first official national record holder in the high jump with a height of 1.395 meter.^[2][3]

In September 1927 she became Dutch national champion in the 4x 100 metres together with Nici Mür, Martha Kolthof and Nettie Grooss with a time of 55 seconds.^[4]

• newspaper articles with Hamerslag — via Delpher