Thelma Kench later Irion (19 February 1914 – 25 March 1985) was a New Zealand sprinter who competed at the 1932 Summer Olympics.

Kench, trained by her father,^[3] competed in the 100 m and held the national title in 1930–1932. Her time equalled the world record, and she was at 16 the youngest to hold the title. Her "husky"^[4] physique was much commented upon in the press,^[5] and she was described as "nuggetty with massive legs".^[6]

Kench's selection had some drama. The New Zealand Amateur Athletic Association (NZAAA) selectors recommended three athletes for the 1932 Olympics in Los Angeles, but because of the extra cost of a chaperone none were women. The NZAAA decided to nominate her, but as the New Zealand Olympic & Commonwealth Games Association (NZOCGA) only had funds to send three, the fourth would be sent at the expense of the NZAAA.^[7] So the Wellington branch of the NZAAA raised £120 for her, although the Otago branch could not raise £50 for Jack Lovelock.^[6] In the Olympic semifinals of the 100 m race in Los Angeles she was third after 50 m but dropped back to sixth.^[1][8] After the Olympics, she gained weight, which was also commented upon by the press,^[9] and retired from track competition in 1933, at age 19.

Kench was born in Palmerston North, and moved to Whanganui.^[10] She married John Henry "Jack" Irion in 1940.^[11][12] They had two sons and two daughters, and lived in Wellington, where she died in 1985, aged 71 years.^[13]