It comes after the airline and operator was forced to pull its Turkey programme this week.
Turkey was removed from Westminster’s quarantine-free travel corridor list on Thursday (1 October).
Jet2 said the decision to increase capacity for Greece and Madeira came in response to "a spike in demand" for October travel.
Additions include:
- More than 25 additional flights to Rhodes, with extra services from Birmingham, East Midlands, Leeds Bradford, Manchester, Newcastle and Stansted;
- 20 additional flights to Kos, with extra services from Birmingham, East Midlands, Leeds Bradford, Manchester and Newcastle;
- More than 15 additional flights to Corfu, with extra services from East Midlands, Leeds Bradford, Manchester and Newcastle;
- Nine additional flights to Funchal (Madeira), with extra services from Birmingham, Glasgow, Manchester and Newcastle.
The additions amount to more than 13,000 extra late summer seats, said Jet2.
The airline and operator continues to serve other destinations in Greece, including Kefalonia, as well as Italy and Cyprus, with availability to Paphos and Larnaca.
Steve Heapy, Jet2.com and Jet2holidays chief executive, said: “There has been a significant spike in demand to Corfu, Kos, Rhodes and Madeira and, as ever, we are the first to step in and meet that demand so that independent travel agents can offer travel to the places where customers want to be.
"Customers are telling us loud and clear that they want to escape the gloom and enjoy a well-earned break, and we know these extra flights will book up very quickly.”