Despite the fact that Milan has a very small amount of green space in comparison to cities of its size, the city does boast a wide variety of parks and gardens. The first public parks were established 1857 and 1862, and were designed by Giuseppe Balzaretto. They were situated in a "green park district", found in the areas of Piazzale Oberdan (Porta Venezia), Corso Venezia, Via Palestro and Via Manin.Most of them were landscaped in a Neo-classical style and represented traditional English gardens, often full of botanic richness.Since 1990 Milan is surrounded by the regional Parco Agricolo Sud Milano which forms a half-circle around the south of the city connecting the Ticino Park in the west and Adda Park in the east. The Park was instituted to safeguard and enhance agricultural landscape and activities, woodlands and punctual natural areas, historical heritage in the suburbs, towns and countryside of Milan, with an overall size of 47,000 hectars.
 
Park of Quarries entrance ("Parco delle Cave"), west Milan.

The most important parks in Milan are: the set of adjacent parks in the west area of the city which belong to the Parco Agricolo Sud Milano (the Park of Quarries, 131 hectars; the "Wood-in-the-city" Boscoincittà, 110 hectars; and the Trenno Park, 59 hectars, whose overall size amount to about 300 hectars), the Sempione Park (near to the Castello Sforzesco), Parco Forlani, Giardini Pubblici, Giardino della Villa Comunale, Giardini della Guastalla and Parco Lambro. Sempione Park is a large public park, situated between the Castello Sforzesco and the Arch of Peace (Arco della Pace), near Piazza Sempione. It was constructed by Emilio Alemagna, and contains a Napoleonic Arena, the Civico Acquario di Milano (Civic Aquarium of Milan), a tower, an art exhibition centre, some ponds and a library.Then there is Parco Forlani, which, with a size of 235 hectares is the largest park in Milan,and contains a hill and a pond. Giardini Pubblici is among Milan's oldest remaining public parks, founded on 29 November 1783, and completed around 1790.It is landscaped in an English garden Neo-classical style, and contains a pond, the Natural History Museum of Milan and the Villa Reale. Giardini della Guastalla is also one of the oldest gardens in Milan, and consists mainly of a decorated fish pond.

Milan also hosts three important botanical gardens: the Milan University Experimental Botanical Garden (a small botanical garden operated by the Istituto di Scienze Botaniche), the Brera Botanical Garden (another botanical garden, founded in 1774 by Fulgenzio Witman, an abbot under the orders of Empress Maria Theresa of Austria, and restored in 1998 after several years of abandonment) and the Cascina Rosa Botanical Garden. On January 23, 2003 a Garden of the Righteous was established in Monte Stella to commemorate those who opposed genocides and crimes against humankind. It hosts trees dedicated to Moshe Bejski, Andrei Sakharov, the founders of the Gardens of the Righteous in Yerevan and Sarajevo Svetlana Broz and Pietro Kuciukian, and others. The decision to commemorate a "Righteous" person in this Garden is made every year by a commission of high-profile characters.