Lekavičius had notable performances with the Lithuania youth national teams, winning two European silver medals, and the world bronze medal in 2013. In 2015, Lekavičius was included into the senior Lithuania men's national basketball team candidates list, by the team's head coach, Jonas Kazlauskas. He was also invited to the team's training camp, and he then made it onto the main national team that competed at the EuroBasket 2015, where he won a silver medal. In 2017, just before the start of the EuroBasket 2017 championship, Lekavičius suffered a foot injury that ultimately sidelined him for two months, and was replaced in the final 12-man squad by Adas Juškevičius.