Johnson was born in Newport, South Wales, on 3 December 1985. She has cerebral palsy, and, at the age of three, was encouraged by her mother to join a group for disabled swimmers to strengthen and relax her muscles. She came to love the sport, competing as an S6 swimmer, and was selected to swim for Team GB at the age of 14. Johnson attended Swansea University and in 2008, completed a degree in business management and finance. She currently lives in Bath, Somerset, and trains with the University of Bath training group, Team Bath. While Johnson was on the aeroplane to the 2008 Summer Paralympics in Beijing, her mother died after a long battle with cervical cancer. She decided to continue with the Games when she was told that the funeral could be held when she returned home. Johnson spends one day a week studying accountancy, and is considering a career in that field when she retires from competitive swimming. She has been in a relationship with Brazilian para-swimmer Phelipe Rodrigues since 2011. In July 2016, Johnson appeared in the eleventh series of Celebrity Masterchef on BBC One. Even after experience on Celebrity Masterchef she once set fire to a hotel, at a wedding, whilst cooking toast.
Career
Swimming
Johnson is significant within the British Para Swimming Team; specialising in breaststroke, she is one of a select few to have won gold medals in the Paralympics, World Championships, and European Championships. At the 2006 IPC Swimming World Championships in DurbanSouth Africa, Johnson won an individual gold medal in the 100 metre breaststroke, and two relay golds. She repeated her breaststroke success at the 2009 event, breaking the world record in the process, and also picked up two individual medleybronze medals. She won gold in the 100 metre breaststroke at the 2008 Summer Paralympics, eleven days after the death of her mother, dedicating the victory to her memory. Johnson's successes were recognised when, in April 2011, she was given the honour of laying the final tile in the competition pool at the London Aquatics Centre. She was also selected as the Paralympic Oath taker for the 2012 Paralympic Games. Johnson added to her Paralympic medal collection at London 2012 Paralympics, as she set a new Paralympic recorden route. Johnson recorded a season's best time of 1:40.90, to take the bronze medal in the SB6 100 m backstroke. In the buildup towards her fourth Paralympics at Rio, Johnson underwent an operation for a hernia. While recovering, she found herself falling behind in her training, which impacted on her preparation for the 2016 Paralympic trials. Her failure to make the trials resulted in her decision to retire from competitive swimming.
Entrepreneurship
In August 2018, Johnson announced starting "The Ability People" an organization that is aimed at recruiting disabled people beside the able-bodied people without discrimination. In 2018, she was listed as one of BBC's 100 Women.
