The week-long summit is expected to attract around 5,000 participants from government, business, and civil society under the theme 'Towards a Common Future'.
The meetings will begin in London from April 16 with three days of forums covering youth, women, business and civil society, and culminate with the official retreat for leaders at Windsor Castle on April 20.
Secretary-General Patricia Scotland said, "CHOGM 2018 promises to deliver transformational change for the people of the Commonwealth. The presidents and prime ministers and other high-level government representatives from one-quarter of the countries of the world are assembling. Through consensus, they will reach agreement on collective action, with the impact of their decisions likely to extend far beyond the boundaries of the Commonwealth."
"Agreement among our culturally diverse and geographically widespread member countries to collaborate and innovate often provides the basis for broader progress regionally and internationally. Immediate impact combined with wider influence make the Commonwealth an unparalleled force for building understanding and cooperation towards realising global goals for social and political progress, inclusive prosperity, and sustainable development," she added.
The themes under consideration by leaders at CHOGM 2018 are - A Commonwealth Blue Charter on ocean governance, a Commonwealth connectivity agenda for trade and investment, a declaration on cybercrime, revised Commonwealth guidelines on election observation in member countries
The Women's, Youth and People's Forums will run concurrently at the Queen Elizabeth II Centre, situated opposite the UK Houses of Parliament. The participants will include Commonwealth leaders, government ministers, and members of the British royal family, senior UN figures, business leaders, civil society activists and literary figures.
The Women's Forum will explore the Commonwealth's role in achieving gender equality in line with UN aspirations and the crucial role women have to play in politics, business and peace building.
The Youth Forum will bring 500 young people together to engage in planning, capacity-building and a General Assembly where they will finalise their priorities on a youth-led action in development. These priorities will be presented to heads of government and implemented by the Commonwealth Youth Council and youth-led organisations across the Commonwealth.
The People's Forum, a joint venture between the Commonwealth Foundation and the UK government, is the single largest gathering of civil society representatives in the Commonwealth and is aimed at discussing key issues facing Commonwealth people. This year's forum will address the theme Inclusive Governance: The Challenge for a Contemporary Commonwealth.
Organised by the Commonwealth Enterprise and Investment Council, in partnership with the City of London, the Forum will discuss a range of issues affecting businesses across the Commonwealth and develop ideas for promoting inclusive economic growth.
April 17 will mark the first time all four forums meet together in plenary.
The opportunity will generate discussion around shared themes and stimulate collaboration between the Commonwealth's main partners. Later, leaders and ministers will attend a Small States Ministerial Meeting.
The Commonwealth has long been an advocate for its 31 small states, which face unique challenges related to climate change and external economic shocks. The issues under discussion are resilience, climate change and disaster risk management.
The Commonwealth Ministerial Action Group which assesses countries at risk of breaching fundamental political values will also meet on April 17.
On April 18, foreign ministers will review the leaders' agenda and receive outcomes from the four forums for consideration by heads, who will meet delegates at a joint forum breakfast on April 19.
The formal opening of CHOGM will take place at Buckingham Palace on the same day, after which leaders will convene for their first executive session.
On April 20, the Commonwealth Games Federation will host a breakfast for heads of government. The summit concludes later that day when leaders will issue their communique and a leaders' statement after their retreat.
It is the second time the UK has hosted CHOGM. The first was in Edinburgh in 1997.