The 31-year-old took gold in the women's pair alongside her close friend Helen Glover at London 2012 and Rio 2016.
Stanning, 31, took gold in the women's pair alongside her close friend Helen Glover at London 2012 and they repeated the feat in Rio de Janeiro earlier this year.
She intends to continue serving as a major in the British army.
"It's hard to identify a key highlight," Stanning said in a statement. "Obviously winning back-to-back Olympic golds is up there, but also our first World Championship gold (in 2014) was a big highlight."
Glover, who is expected to continue her career, said: "Thank you, Heather, not just for the success we shared, but for making it the most fun journey possible."