Dimuth Karunaratne is married to the model and teledrama actress, Anuradha Kurukulasooriya. The wedding was held on 29 April 2015 at Gangaramaya Temple, Colombo with the presence of President Maithreepala Sirisena. The home coming party was celebrated at Avenra Garden Hotel, Negombo on next day.
Karunaratne attended the prestigious St. Joseph's College, Colombo, which has produced a number of Sri Lankan test cricketers such as Chaminda Vaas, Angelo Mathews and Thisara Perera. He was a record-breaking batsman for the school's cricket team. After featuring in Sri Lanka's Under-19 and A squads, he was called into the senior One Day International (ODI) team for the series against England and Scotland in June and July 2011. He played in two matches on the tour, scoring four runs against England in Manchester, and 60 against Scotland in Edinburgh. He was selected in Sri Lanka's Test squad for its tour of South Africa at the end of 2011, although did not play in any of the three Tests.
He was recalled into the Test squad for the home Tests against New Zealand during late 2012. He got the opportunity due to Tillakaratne Dilshan being unable to make the XI because of an injury. He debuted in the first Test in that series, in Galle, only to get out for a duck in the first innings. However, he came back strongly in the 2nd innings with an unbeaten half century and hit the winning runs as well. Following the New Zealand series he was called into the test squad which was to tour Australia for a three test match series. During the first two tests in that series he failed to have an impact as he struggled against the Australian pace attack. In the final test of the series in Sydney he managed to get his highest test score of 85 in the second innings.
His maiden century came against New Zealand on 28 December 2014 at Hagley Oval, Christchurch. He scored 152 runs from 363 balls in the second match of the series, where Sri Lanka in deep trouble of even draw the match. Eventually, Sri Lanka lost the match.
He was picked to the original squad of 2015 ICC Cricket World Cup, but during a practice match, he broke a bone in his right hand and was removed from the team after the match against England. Kusal Perera replaced to Dimuth's place.
His second Test hundred came against Pakistan in Kandy, scored 133 runs in first innings of the third match of the series. As his first Test century became waste, nothing different in this time. Sri Lanka lost the match by 7 wickets.
His highest score in Test cricket was recorded during the first Test against West Indies in 2015 at Galle. He scored magnificent 186 runs and unfortunately got out in bowling of Marlon Samuels. He with Dinesh Chandimal, who also scored a century, recorded the highest partnership for the third wickelt at Galle, by scoring 238 runs. Sri Lanka easily defeated West Indies by an innings and 5 runs.
Karunaratne showed very poor performance at home against Australia. He was trapped lbw and caught five times to Mitchell Starc in the first over of the each innings. He only scored 41 runs in three matches, including five single-digit scores, at average of 6.83 in six innings against Australia. Despite his poor performance, Sri Lanka whitewashed Australia 3-0 for the first time.
Karunaratne was named captain of the A team for the first two four-day games at home against West Indies A. He scored 131 in first innings and 39* in second innings, guides Sri Lanka A to seven-wicket win. This strong comeback gave him to name for the Test team for Zimbabwe tour in late October 2016.
During the first innings of the first Test against Zimbabwe, Karunaratne scored a fifty and in second innings scored his fourth Test century. Sri Lanka finally won the match by 225 runs. In the second Test, he scored 88 runs in the second innings, guided Sri Lanka to post impossible chasing to Zimbabwe. With impressive bowling by skipper Rangana Herath, Sri Lanka won the match by 257 runs, and whitewashed the series 2-0. Karunaratne won player of the series for his batting performance, scored 280 runs at an average of 70.00.
He took his maiden Test wicket by dismissing Indian batsman Cheteshwar Pujara during the second test at SSC. In the second innings of the same match, he scored his sixth century, in Sri Lanka's follow-on. However, Karunaratne and Kusal Mendis had a partnership of 191, Sri Lanka lost the match by an innings and 53 runs. This was the first time that India won a test match by an innings against Sri Lanka in Sri Lanka.In this table Ct., refers to the Catches.