On 3 April 2018, Philip was admitted to King Edward VII's Hospital for a planned hip replacement, which took place the next day. This came after the Duke missed the annual Maundy and Easter Sunday services. On 12 April, his daughter, Princess Anne, spent about 50 minutes in the hospital and afterward said her father was "on good form". He was discharged the following day.
Following Judge's Moro issuing of an arrest warrant for the ex-president, on April 6, 2018, Lula appealed to the UN"s Human Rights Committee to ask the government to prevent his arrest until he had exhausted all appeals.
On April 10 and April 11, 2018, Zuckerberg began testifying before the United States Senate Committee on Commerce, Science, and Transportation regarding the usage of personal data by Facebook in relation to the Facebook–Cambridge Analytica data breach.
On 17 April 2018, Brazilian senators who were members of the legislature's Human Rights Commission, the Argentinian Nobel Prize laureate, Adolfo Perez Esquivel and the former president of Uruguay, José Pepe Mujica were not allowed to visit Lula in prison to acquire information of violation of Lula’s human rights.
On 20 April 2018, Ardern attended the Commonwealth Heads of Government Meeting 2018 in London, where she was selected to deliver a toast to the Commonwealth at a state banquet of world leaders. She also had her first private audience with Queen Elizabeth II.
On 27 April 2018, it was announced that North Korea and South Korea agreed to talks to end the ongoing 65-year conflict. They committed themselves to the complete denuclearization of the Korean Peninsula.