The launch brings Neapolitan-style chain's tally of UK sites to 19, the majority of which are concentrated in the capital.
Firezza's menu consists over of 22 different topping combinations on a 'quarter metre' or 'half metre' base.
Flavour combinations include classics such as the margherita .with mozzarella and fresh basil; Sicilian-style salsiccia made with a white base, Sicilian-style sausage, Italian wild broccoli, cream, garlic butter, mozzarella and fresh red chilli; and the Fiorentina with Firezza home-made tomato sauce, baby spinach leaves, mozzarella, oven-roasted tomatoes, feta, oregano and grated vegetarian cheese.
Side dishes, meanwhile, include a selection of arancini; garlic bread sticks; white truffle potato wedges; and focaccia with pancetta and buffalo mozzarella.
A selection of Italian beers and wines are also available alongside soft drinks and classic Italian desserts such as tiramisu and apple and frangipane pie.
Firezza was founded in 2011 by Bosnian entrepreneur Edin Basic, and at its peak grew to 22 locations including a now closed eat-in restaurant in Soho
It was acquired by PizzaExpress in early 2016, but was subsequently offloaded by the casual dining chain in late 2017.
Firezza is now owned by Net Gold Star Ltd.