Dennison was born in South Africa and her mother swam for Zambia. She is a former gymnast and was the first British junior to vault over 4.00m. She finally broke Janine Whitlock's British indoor record at the 2009 Aviva UK Indoor Champs, before improving the mark one week later at the Aviva Birmingham Indoor Grand Prix with a height of 4.46m, despite having back surgery in the off-season and the reward is even more surprising as she did not intend to do an indoor campaign. In Turin, Dennison placed sixth, which surpassed many people's predictions. Dennison capped off a fine indoor season with an outright British record in Oyannax, vaulting 4.49m, to improve Whitlock's record by 2cm. Kate hails from a sporty family and once finished 4th in the U12 National Gymnastic Championships. Her brother was an international gymnast when younger. She has a degree in psychology from Staffordshire University. Her hobbies outside of athletics include: watching films, photography and has also down some rock climbing. She qualified for London 2012 with silver at the Olympic trials and won a Commonwealth bronze in 2010.