Balapuwaduge Kusal Gimhan Mendis (কুশল মেন্ডিস) is a professional Sri Lankan cricketer who plays in all forms of the game and a former ODI captain of the national team. He only played sixteen first-class matches before playing for the national side. In November 2017, he was named the One Day International (ODI) batsman of the year for the 2016–17 season at Sri Lanka Cricket's annual awards.

In 2013, Mendis was adjudged as the schoolboy cricketer of the year and had captained the national youth and the Prince of Wales College, Moratuwa teams in his formative years.

In March 2018, Mendis was named in Dambulla's squad for the 2017–18 Super Four Provincial Tournament. In the following month, he was also named in Dambulla's squad for the 2018 Super Provincial One Day Tournament. In August 2018, Mendis was named to Galle's squad for the 2018 SLC T20 League. He was the leading run-scorer for Galle in the tournament, where he scored 182 runs in six matches. In March 2019, he was named in Galle's squad for the 2019 Super Provincial One Day Tournament.

In October 2020, Mendis was drafted by the Kandy Tuskers for the inaugural edition of the Lanka Premier League. In November 2021, he was selected to play for the Galle Gladiators following the players' draft for the 2021 Lanka Premier League. In July 2022, he was signed by the Galle Gladiators for the third edition of the Lanka Premier League.

In 2014, Mendis was named as the captain for the 2014 ICC Under-19 Cricket World Cup. After strong performances in U-19 career, Mendis became the 132nd Test player for Sri Lanka, after gaining his cap during the second Test of Sobers-Tissera Trophy against West Indies. He scored 13 runs in the first innings and 39 runs in the second innings. Then in 2016, Mendis was named in the Sri Lanka squad for the tour of England. In the first Test, he got a duck in the first innings, but scored his maiden test half-century with 53 runs in the second innings.

On 28 July 2016, Mendis scored his maiden Test century during the first Test against Australia at the Pallekele Cricket Stadium. He became the youngest Sri Lankan to score a century against Australia and also the highest score against Australia on home soil. Sri Lanka won the match by 106 runs, which was only their second Test win against Australia. Mendis won the Man of the Match award for his performance.

In the fifth match of the Tri-series in Zimbabwe against the West Indies, Mendis scored match-winning 94 runs and made 94-run partnership with Niroshan Dickwella. Sri Lanka later posted 330 runs off 50 overs, which was recorded as the highest total by Sri Lanka against the West Indies. Sri Lanka won the match by one run and reached the final, where Mendis won the man of the match award. In the final against Zimbabwe, Mendis scored another fifty, guiding the team to win the series by 6 wickets. His all-round performances in the series gave him his first Player of the series award.

On 28 June 2021, Sri Lanka Cricket (SLC) suspended Mendis, Danushka Gunathilaka and Niroshan Dickwella after they breached the team's bio-secure bubble during Sri Lanka's tour of England. All three players were seen in the city centre of Durham, with SLC sending them all back home ahead of the ODI matches. In July 2021, following the outcome of the incident, Mendis was suspended from playing in international cricket for one year. Sri Lanka Cricket agreed to lift the ban early, rescinding the punishment in January 2022.

In July 2020, Mendis was arrested after being involved in a fatal road accident in Panadura. Mendis was driving a vehicle that hit an elderly cyclist, who later died in hospital. A day after the incident, Mendis was released on bail. On 12 February 2021, Mendis married his wife in Colombo. In June 2022, Mendis' wife gave birth to a baby girl.