In July 2018, he was named in Sri Lanka's
One Day International (ODI) squad for their series
against South Africa. He made his ODI debut for Sri Lanka against
South Africa on 1 August 2018. He was on the verge of making his test debut during the
home test series against Bangladesh way back in April 2021 as an injury replacement to
Lasith Embuldeniya but he was not included in the squad for failing
skinfold fitness tests and
Praveen Jayawickrama who had just 10 first-class games experience under his belt got the nod over the experienced premiere spinner at domestic level. The reason for his exclusion was initially reported by media that Jayasiriya had failed to complete the mandatory two kilometre fitness run inside eight minutes which was in force during the tenure of
Mickey Arthur as head coach but the reports were rubbished by SLC as it clarified that Jayasuriya was snubbed based on his skinfold tests. Following Jayawickrama's incredible start to test cricket with twin fifers on debut against Bangladesh, the hopes of Jayasuriya making a case for himself at test level started to wane and Jayasuriya fell under the radar. Despite being a consistent performer at first-class level, Jayasuriya was made to wait for too longer. In July 2022, he was added to Sri Lanka's
Test squad for the second match
against Australia. He was included to the final test at the last minute under most dramatic circumstances as Jayawickrama was diagnosed with
COVID-19 after testing positive while lead spinner Lasith Embuldeniya was dropped by selectors due to poor run of form. With the lack of backup frontline spinners, captain
Dimuth Karunaratne brought Prabath Jayasuriya in the lineup to face Australia in the decisive test having played alongside him for the same club. He made his Test debut on 8 July 2022, for Sri Lanka against
Australia. On his debut, he took a
five-wicket haul, with figures of 6/118. In the second innings of the match, he took
another five-wicket haul, to finish with the best bowling figures for a Sri Lanka player on debut and fourth best overall, with 12 for 177. He also became the second bowler for Sri Lanka to take
two five-wicket hauls on Test debut after Praveen Jayawickrama. He was adjudged man of the match award for his match winning bowling performance. He also ended up as the leading wicket taker of the series with 12 scalps despite missing the first test. In July 2022, he was called to the Test squad as the premium spinner for the series
against Pakistan. During the first test of the series against Pakistan, he picked up his third career five-wicket haul in an innings of a test match to become only the third bowler to grab five wicket hauls in his first three test innings since debut after
Tom Richardson and
Clarrie Grimmett. With record 21 scalps after just two test appearances, he is only behind
Narendra Hirwani and
Alec Bedser in picking up most test wickets after their first two test matches. He also became the third Sri Lankan bowler after
Muttiah Muralitharan and
Rangana Herath to secure three consecutive five wicket hauls in consecutive innings in test cricket. During the second test of the series against Pakistan, he picked up his fourth career five-wicket haul in an innings of a test match to become the seventh bowler overall to take fifers in first three test match appearances and also to become the fifth bowler to claim four five-wicket hauls in first three test appearances from debut. He was awarded player of the series for his impressive performances with the ball which helped Sri Lanka to level the two match test series 1–1 against Pakistan and he also ended up as the top wicket taker of the series with 17 scalps. He made giant leaps in test cricket after a prolific start to his test career by picking up 29 wickets in his first three test matches and he is only behind Hirwani and
Charles Turner for taking most number of wickets after their first three test matches. During the
New Zealand tour in March 2023, he took only 4 wickets for 224 runs in two matches, where Sri Lanka lost the series 2-0. However,
against Ireland in the home test series in April 2023, Jayasuriya took his second ten-wicket haul with 7–52 in first innings and 3–56 in the second innings. Sri Lanka finally won the match by an innings and 280 runs and Jayasuriya won the man of the match award. In the second match of the series, he took another five-wicket haul of 5 for 174 runs, his sixth five-for in the format. After a strong batting performance by Sri Lanka, Ireland suffered another defeat by an innings and 10 runs, where Jayasuriya won the player of the series award for taking 17 wickets in the series. In the process, he also became the fastest spinner to 50 Test wickets in just seven matches.
Against Pakistan in July 2023, he took only 9 wickets and Sri Lanka lost the series 2-0. On 3 February 2024,
against Afghanistan, Jayasuriya took his 7th Test five-wicket haul with 5-107 in the second innings. Sri Lanka eventually won the one-off test series by 10 wickets and Jayasuriya won the man of the match award for his 8 dismissals in the match. In the first Test
against New Zealand, Jayasuriya delivered a match-winning five-wicket haul in the second, where Sri Lanka won the match by 63 runs. This was his eighth five-wicket haul, and seventh in Galle. With the match figures of 4/136 in first innings and 5/68 in the second innings, he won the man of the match award. In the first innings of the second Test, Jayasuriya took his ninth five-wicket haul and finished with 6 for 42, where New Zealand bundled out for 88, their lowest all-out total against Sri Lanka. In the second innings, he took 3 more wickets, where Sri Lanka won the match by an innings and 154 runs and series 2–0, where Jayasuriya won the player of the series award. ==Awards==