She’s also Team GB’s most decorated Olympian of all time after securing the silver medal in the women’s double sculls in the Olympics.
Grainger’s medal she won on Thursday in Rio is her fifth.
Apart from her latest medal, the 40-year-old won a gold medal in 2012 in London in the double sculls, a silver in 2008 in Beijing in the quadruple sculls, a silver in 2004 in Athens in the coxless pair and a silver in 2000 in Sydney in the quadruple sculls.
When not working on her sports career, Grainger is a Chancellor of Oxford Brooke’s University, a role she was appointed to in 2015.
Previous holders of her office are Shami Chakrabarti and Helena Kennedy QC.
In an interview with the BBC, Grainger talked about the bittersweet moment, as it is understood her latest race in Rio will be her last.
She said that winning her latest medal is an emotional roller coaster, saying the day after her victory is the hardest.
“I think people who know me wouldn't expect me to do anything beyond this point,” she said.
“London was an incredible end point in my career but for personal reasons I wanted to come back and have another go.
“It has been even better than most people expected, including myself, but there is a limit to my abilities.”
Characterising the day after as “a bit odd,” she said “There is nothing left to be done. We had this driving focus for a long time, so it is a very empty feeling.”
“So you do things like your laundry and menial bits and pieces. But now we can kick back and watch other Team GB athletes for the rest of the Games,” she said. “It is an emotional up and down, but the overwhelming thing is I am very proud and very happy.”
Katherine Grainger has an honours law degree from Edinburgh University, a masters degree in medical law and ethics from Glasgow University and a doctorate on sentencing and the law of homicide from King’s College University.