As chief adviser to the Sovereign, he oversaw the transition from Queen Elizabeth II to King Charles III.

After the death of Elizabeth II in 2022, Young served as joint principal private secretary to King Charles III until he stepped down in May 2023.

[5][1] As Deputy Private Secretary he played a key role in the planning of the Queen's visit to the Republic of Ireland in 2011.

He is credited with assisting the Queen in writing the highly praised speech, which she began with a few words in the Irish language.

[7][8][9] Young led the national planning of the Diamond Jubilee of Queen Elizabeth II, which took place in 2012.

[8] He persuaded Elizabeth to take part in the James Bond helicopter sketch in the opening ceremony of the 2012 Summer Olympics in London.

Lacey charged that Young "should have sat down with Meghan, Duchess of Sussex and explained precisely" her "relatively minor ranking" after her marriage to Prince Harry in 2018.

[24] In July 2024 Young was appointed as Senior Adviser to Pictet, the Swiss multinational private bank and financial services company.

[25] Young was played by Alex Jennings in the 2024 three-part Amazon Prime drama A Very Royal Scandal.

The drama concludes with a stand-off between Young and Prince Andrew (played by Michael Sheen) following the disastrous BBC Newsnight interview of 2019.