The square is the site of concerts, art displays, a weekly farmers' market, the winter festival of lights, and other public events, including demonstrations.

The square has a reflecting pool, a peace garden, a permanent stage and several sculptures, including Three Way Piece No.2: Archer by Henry Moore.

Outside the walkway are treed lawns dotted with various other memorials and monuments, such as Oscar Nemon's statue of Sir Winston Churchill (c. 1977),[3] and a Roman column.

[7] The elevated concrete walkway connects to the podium of the City Hall at the height of its roof and extends around the perimeter of the square.

"[3] The sundial at the south end of the garden pre-dates the peace memorial; inscribed with the words "In appreciation of the opportunity to serve," it was originally installed in 1969, designed by G.R.

Fifteen years later, during the city's sesquicentennial, then Prime Minister of Canada Pierre Trudeau turned the first sod for the Peace Garden, which was to sit immediately north of, but also incorporate, the pre-existing sundial.

The gazebo is a stone-clad cube with arched openings on all sides, capped with a pitched roof, and with one corner of the structure deconstructed, to signify conflict and the fragility of civilization.

The fountain's pool encroaches into this removed corner, with an eternal flame placed in the water so as to appear as though it supports the pavilion structure, to symbolize hope and regeneration.

[12] Following World War II, the City of Toronto government prepared to construct a civic square in Chinatown, through a by-law which prohibited further development except for public purposes or parking lots.

[11] With voter approval in 1947, the city began acquisition of sites inside Chinatown from 1948 to 1958, with expropriation and demolition of various shops and restaurants in 1955 for the development of the square.

The south side was vacant at the time of the City Hall opening but was eventually occupied by a new hotel, connected by a pedestrian bridge over Queen Street to the square.

To add decoration to the square, City Hall architect Viljo Revell wanted a sculpture by British sculptor Henry Moore.

[16] After the 1972 Summit Series, the Canadian men's ice hockey win was feted with a public ceremony hosted by the mayor and the Ontario Premier.

[19] The plans included demolishing and replacing the food and skate rental kiosk, along with the addition of an upper level roof terrace overlooking the square; a two-level restaurant at the southwest corner of the square, with outdoor patio and terrace dining; a glass tourist information pavilion at the Queen and Bay Streets corner; a versatile stage structure under a glazed roof canopy; redesigned landscaping along the edges of the square that increases the number of trees, planting, mixed tree species; expansion and enhancement of the Peace Garden, with a flowering tree grove, eternal flame, and reflecting pool; landscaping and a café on the podium roof of City Hall; a restaurant and bar at the Observation Deck level of the east tower of City Hall; upgrading the overhead walkways with wood decking, seating, glass balustrades, light wells and improved access; and a seasonal disappearing water fountain in the centre of the square.

[19] Sustainable design elements were also included so as to conform to Toronto's Green Standard, including a soil regeneration strategy, improved tree planting conditions, and increased biomass and number of trees; facilities for cyclists and the promotion of cycling; an improved pedestrian environment; the control of light pollution; energy efficient design; renewable energy features; opportunities for public education; attention to the on-site microclimate; and local sourcing of materials.

[20] On May 29, 2010, Mayor David Miller officially opened the first phase of the Revitalization project: the Podium Green Roof Garden.

After the Toronto Raptors won the 2019 NBA Finals, the subsequent parade on June 17, 2019, in Toronto culminated at Nathan Phillips Square, with two million people in total attendance, the largest public gathering in one place for one event in Canadian history; a shooting broke out in a portion of the square where four people were shot and injured.