The capital Rome is the largest Italian city, as regards the inhabitants of its municipality, which is also the widest in the country.Taking into consideration the entire urban agglomeration, Milan is instead the city with the most inhabitants of the Peninsula, its municipality is in fact decidedly less large than that of Rome, but many neighboring cities and towns are all togheter with the Lombard capital.
In Italy there are 2 cities over a million inhabitants and 6 with at least half a million people, while there are four agglomerations over a million, corresponding to the first cities in this ranking.
The region with the most cities over 100,000 inhabitants is Emilia-Romagna with 9, while there are not even one in Basilicata, Marche, Molise and Aosta Valley; the only non-provincial capital on the list is Giugliano in Campania.
| City | Population | Municipality area | Elevation | Region |
| Rome | 2,783,800 | 1,287 Kmē | 20 m. | Lazio |
| Milan | 1,397,700 | 182 Kmē | 122 m. | Lombardy |
| Naples | 940,900 | 119 Kmē | 17 m. | Campania |
| Turin | 848,200 | 130 Kmē | 239 m. | Piedmont |
| Palermo | 640,700 | 161 Kmē | 14 m. | Sicily |
| Genoa | 558,900 | 240 Kmē | 19 m. | Liguria |
| Bologna | 394,500 | 141 Kmē | 54 m. | Emilia-Romagna |
| Florence | 359,800 | 102 Kmē | 50 m. | Tuscany |
| Bari | 313,000 | 117 Kmē | 5 m. | Apulia |
| Catania | 294,300 | 183 Kmē | 7 m. | Sicily |
| Verona | 257,800 | 199 Kmē | 59 m. | Veneto |
| Venice | 255,600 | 416 Kmē | 2 m. | Veneto |
| Messina | 225,500 | 214 Kmē | 3 m. | Sicily |
| Padua | 208,300 | 93 Kmē | 12 m. | Veneto |
| Parma | 200,200 | 261 Kmē | 57 m. | Emilia-Romagna |
| Trieste | 199,800 | 85 Kmē | 2 m. | Friuli-Venezia Giulia |
| Brescia | 195,100 | 90 Kmē | 149 m. | Lombardy |
| Prato | 193,600 | 97 Kmē | 61 m. | Tuscany |
| Taranto | 189,400 | 250 Kmē | 15 m. | Apulia |
| Modena | 188,000 | 183 Kmē | 34 m. | Emilia-Romagna |
| Reggio di Calabria | 173,500 | 239 Kmē | 31 m. | Calabria |
| Reggio nell'Emilia | 169,800 | 231 Kmē | 58 m. | Emilia-Romagna |
| Perugia | 164,100 | 450 Kmē | 493 m. | Umbria |
| Ravenna | 157,400 | 654 Kmē | 4 m. | Emilia-Romagna |
| Livorno | 156,000 | 104 Kmē | 3 m. | Tuscany |
| Cagliari | 149,500 | 85 Kmē | 6 m. | Sardinia |
| Rimini | 148,700 | 136 Kmē | 5 m. | Emilia-Romagna |
| Foggia | 148,300 | 509 Kmē | 76 m. | Apulia |
| Ferrara | 132,300 | 405 Kmē | 9 m. | Emilia-Romagna |
| Salerno | 130,200 | 60 Kmē | 4 m. | Campania |
| Latina | 126,600 | 278 Kmē | 21 m. | Lazio |
| Sassari | 124,100 | 547 Kmē | 225 m. | Sardinia |
| Monza | 124,000 | 33 Kmē | 162 m. | Lombardy |
| Trento | 120,500 | 158 Kmē | 194 m. | Trentino-South Tyrol |
| Bergamo | 119,700 | 40 Kmē | 249 m. | Lombardy |
| Pescara | 119,500 | 34 Kmē | 4 m. | Abruzzo |
| Giugliano in Campania | 118,900 | 95 Kmē | 97 m. | Campania |
| Syracuse | 118,100 | 208 Kmē | 17 m. | Sicily |
| Forlė | 117,500 | 228 Kmē | 34 m. | Emilia-Romagna |
| Terni | 109,300 | 212 Kmē | 130 m. | Umbria |
| Vicenza | 109,300 | 81 Kmē | 39 m. | Veneto |
| Bolzano / Bozen | 107,800 | 52 Kmē | 262 m. | Trentino-South Tyrol |
| Piacenza | 103,300 | 118 Kmē | 61 m. | Emilia-Romagna |
| Novara | 101,900 | 103 Kmē | 162 m. | Piedmont |
* data updated to 1 January 2021 - source ISTAT
In the following table the 10 urban agglomerations with at least half a million inhabitants, the data refer to urban areas, not to be confused with metropolitan ones, as cities with urban contiguity are taken into consideration, not those with administrative or infrastructure and transport correlation.
| City | Urban aggl. | Other municipalities | Region |
| Milan | 4,994,000 | Monza, Sesto San Giovanni, Busto Arsizio, Cinisello Balsamo, Legnano, Gallarate, Rho | Lombardy |
| Naples | 3,303,000 | Giugliano in Campania, Torre del Greco, Pozzuoli, Casoria, Castellamare di Stabia, Afragola | Campania |
| Rome | 3,207,000 | Guidonia Montecelio, Fiumicino, Pomezia, Tivoli | Lazio |
| Turin | 1,431,000 | Moncalieri, Collegno, Rivoli, Nichelino, Settimo Torinese | Piedmont |
| Florence | 770,000 | Prato, Scandicci, Sesto Fiorentino, Campi Bisenzio | Tuscany |
| Palermo | 737,000 | Monreale | Sicily |
| Catania | 647,000 | Acireale, Misterbianco | Sicily |
| Bologna | 532,000 | Casalecchio di Reno, San Lazzaro di Savena | Emilia-Romagna |
| Genoa | 531,000 | Recco | Liguria |
| Bergamo | 508,000 | Seriate, Dalmine | Lombardy |
* 2021 estimates - source DEMOGRAPHIA WORLD URBAN AREAS