Views in Florence fall into three categories: Lungarno river views with Ponte Vecchio in frame; Duomo and Palazzo Vecchio views from central rooftop terraces; and panoramic hillside views from the Fiesole and Arcetri villas above the city. Each offers a different relationship with Florence's architecture, and the best hotels for views have understood which perspective they're selling.
The Lungarno position — particularly on the north bank between Piazza Ognissanti and the Ponte Vecchio — is the most coveted in Florence. Portrait Firenze and Hotel Lungarno have rooms with direct Ponte Vecchio views, and the evening light on the medieval bridge from a Lungarno terrace is one of Europe's great travel images. The Continentale's rooftop terrace offers the same view from above.
For the Duomo view, rooftop terraces are the answer. J.K. Place Firenze has the finest hotel rooftop view of the cathedral; the Rinascente department store's rooftop café (technically not a hotel but relevant to any view-seeking traveller) offers the closest position. The Brunelleschi Hotel's Byzantine tower has direct Duomo views from its upper levels.
The hillside perspective — from the Fiesole hills, from Piazzale Michelangelo, from Villa Cora — shows Florence as a medieval city set in the Arno valley, a skyline dominated by the Duomo and punctuated by cypress trees and Renaissance towers. Il Salviatino and Belmond Villa San Michele on the Fiesole slopes offer the finest hotel expressions of this view.
A practical note: Florentine hotel rooms marketed as having 'views' vary enormously in quality. Always request a specific room type — 'Ponte Vecchio view' at Lungarno properties, 'Duomo view' at J.K. Place, 'garden view' at the Four Seasons — rather than accepting a generic superior room that may face a courtyard or side street.