Saina Nehwal (pronunciation^ⓘ; born 17 March 1990) is an Indian badminton player. A former world no. 1, she has won 24 international titles, which includes ten Superseries titles. Although she reached the world's 2nd in 2009, it was only in 2015 that she was able to attain the world no. 1 ranking, thereby becoming the only female player from India and thereafter the second Indian player – after Prakash Padukone – to achieve this feat. She has represented India three times in the Olympics, winning a bronze medal in her second appearance at London 2012.

Nehwal has achieved several milestones in badminton for India. She is the only Indian to have won at least one medal in every BWF major individual event, namely the Olympics, the BWF World Championships, and the BWF World Junior Championships. She is the first Indian badminton player to have won an Olympic medal, the first Indian to have reached the final of the BWF World Championships, and the first Indian to have won the BWF World Junior Championships. In 2006, Nehwal became the first Indian female and the youngest Asian to win a 4-star tournament. She is also the first Indian to win a Super Series title. In the 2014 Uber Cup, she captained the Indian team and remained undefeated, helping India to win a first-ever Uber Cup bronze medal. Nehwal also became the first Indian to win two singles gold medals (2010 and 2018) at the Commonwealth Games.

Considered one of India's most successful badminton players, Nehwal is credited for increasing the popularity of badminton in India. In 2016, she was conferred the Padma Bhushan – India's third highest civilian award. Previously, she had also received the nation's top two sporting honours, namely the Major Dhyan Chand Khel Ratna and the Arjuna Award. Nehwal is a philanthropist and was ranked 18th on the list of most charitable athletes in 2015.

Saina Nehwal, the daughter of Harvir Singh Nehwal and Usha Rani Nehwal, was born in Hisar, Haryana. She has an elder sister named Chandranshu Nehwal. Her father, who has a PhD in agricultural science, worked at Chaudhary Charan Singh Haryana Agricultural University. She completed her first few years of schooling at Campus School CCS HAU, Hisar. She finished 12th grade from the St. Ann's College for Women, Hyderabad.

When her father was promoted and transferred from Haryana to Hyderabad, she took up badminton at the age of eight to express herself, as she did not know the local language well enough to socialise with other kids. Her parents played badminton for a number of years. Her mother, Usha Rani, was a state level badminton player in Haryana. Nehwal took up badminton to fulfill her mother's dream of becoming a national level badminton player, while her sister played volleyball. Her father, who was among the top players in the university circuit, used his provident fund to invest in good badminton training for her. After moving to Hyderabad in 1998, she was enrolled in a karate class by her parents, which she continued for a year and earned a brown belt.

She trained under Pullela Gopichand in his academy Gopichand Badminton Academy. In 2014, she parted with Gopichand and joined Prakash Padukone Badminton Academy in Bangalore and trained under U. Vimal Kumar under whose training she became World number one; she later in 2017 returned to train under Gopichand. In his book 'Dreams of a Billion: India and the Olympic Games', Gopichand said that he felt miserable when she left him and went to train in Bangalore.

Nehwal and her family speak the Haryanvi language at home. She is a fan of actors Shah Rukh Khan and Mahesh Babu and cricketer Chris Gayle. She is in the process of opening a badminton academy in her native state of Haryana.

She married a badminton player, Parupalli Kashyap in a private ceremony on 14 December 2018. On 14 July 2025, Nehwal announced separation from her husband in an Instagram post. However, on 2 August 2025, she shared on Instagram that the couple was "trying again" and working on their relationship.