Nottingham Open, officially named Nature Valley Open for sponsorship reasons, is a tennis tournament for men and women held in Nottingham, United Kingdom, played on outdoor grass courts at the Nottingham Tennis Centre. After being discontinued in 2008, it was briefly re-established as an ATP World Tour 250 event on the men's tour in 2015 & 2016, before being downgraded to a Challenger event in 2017, and an international event on the women's tour. The tournament is held in June as a preparation before the third Grand Slam event of the season, the oldest and widely considered the most prestigious tennis tournament, The Championships, Wimbledon.