The airline and operator on Wednesday (8 January) set out full details of its plans, which include six new destinations – Mykonos, Skiathos, Santorini, Kalamata, Preveza and Lesbos.
Jet2 will operate to 14 Greek destinations in total, and has placed more than a dozen new routes on sale for summer.
At peak times, Jet2 will operate more than 220 weekly flights, an increase of more than 50% on last year with in excess of 70 new weekly services available for agents to book.
The business said the expansion underlined its "commitment to Greece, its economy and tourism industry".
"With multiple weekly flights to many Greek destinations, this means independent travel agents can offer holidaymakers complete flexibility over how long they choose to holiday for," said Jet2.
Jet2 is taking on new staff to support its expansion plans in Greece, and has pledged to work with hoteliers and the Greek National Tourism Organisation to promote the destination.
This summer, Jet2.com will operate up to four weekly services to Mykonos from Manchester and Stansted, three to Lesbos and three to Kalamata; and four weekly services to Santorini, eight to Skiathos and seven to Preveza from Birmingham, Manchester and Stansted.
The carrier will add capacity elsewhere in the region too. This includes growing Corfu flights from 20 to 30 a week, Crete flights from 38 to 46, and Zanta flights from 24 to 30. Jet2holidays, meanwhile, is offering some 5,000 two- to five-star properties in Greece this summer.
Steve Heapy, Jet2.com and Jet2holidays chief executive, said: "Since we started operating to Greece, our commitment to this fantastic country has been constant and unwavering.
"Today’s announcement [Wednesday] underlines our commitment meaning that in summer 2020, we will fly more than half a million extra holidaymakers to Greece and its islands.
"With six brand new destinations, 14 destinations on sale in total, and significant investment to support this growth, [this] announcement is a clear signal of just how committed we are to Greece."
