In 2005, Wizz Air was still a relatively young airline, but it had already begun to build a recognizable presence in the European low-cost sector. Throughout 2005, Wizz Air expanded aggressively from Hungary and Poland, which became two of the airline’s most important markets. Poland in particular represented a major opportunity because millions of Polish citizens began travelling abroad after Poland joined the European Union in 2004. Wizz Air rapidly introduced services connecting Polish cities with destinations in the United Kingdom, Germany, Italy, France, and Scandinavia.

One of the defining features of Wizz Air during 2005 was its fleet expansion centered around the Airbus A320 family. The airline operated the Airbus A320-200, a modern and fuel-efficient aircraft well suited for low-cost operations. Wizz Air’s decision to standardize its fleet around a single aircraft type allowed the airline to simplify crew training, maintenance, and scheduling. During 2005, additional Airbus A320 aircraft were delivered to support network expansion.

Wizz Air added routes to major Western European cities including London, Paris, Rome, Barcelona, Dortmund, Stockholm, and Brussels. Many of these routes specifically targeted migrant workers and leisure travellers seeking affordable fares.

The year 2005 also marked increasing competition between Wizz Air and other emerging low-cost carriers in Eastern Europe. Ryanair was expanding into the region, while traditional airlines such as Malev Hungarian Airlines and LOT Polish Airlines attempted to defend market share. The airline developed a reputation for very low fares combined with extensive ancillary revenue generation through baggage fees, onboard sales, and optional services.

During 2006, Wizz Air continued to receive additional Airbus A320 aircraft, enabling the airline to sustain high growth rates. The airline configured its Airbus A320 aircraft in a high-density single-class layout. Wizz Air launched new connections to airports such as Milan Bergamo, Rome Ciampino, and Barcelona Girona.

By 2007, the company continued opening new operational bases and adding destinations throughout Europe. Romania and Bulgaria joined the European Union in January 2007, creating new opportunities for expansion from Bucharest, Sofia, and other Eastern European airports.

The airline also expanded into Ukraine and other non-EU Eastern European markets during 2007. New routes connected cities such as Kyiv with destinations in Western Europe.

In January 2008, flights started from Gdansk to Gothenburg, Bournemouth and Coventry. Throughout 2008, Wizz Air expanded routes across Central, Eastern, and Western Europe. The airline maintained its commitment to operating only Airbus A320-family aircraft, reinforcing operational simplicity and reducing costs.

The global financial crisis beginning in 2008 created significant uncertainty within the airline industry. Wizz Air, however, continued pursuing a low-cost strategy designed to attract budget-conscious travellers during difficult economic conditions. This resilience helped establish Wizz Air as one of the stronger low-cost airlines in Europe entering the next decade. However, that year Wizz Air Ukraine, was officially established and commenced operations on 11 July 2008 with its first flights from Kyiv International Airport (Zhulyany). Using two Airbus A320 aircraft transferred over from the main airline. Over the following years, Wizz Air Ukraine expanded routes linking Ukrainian cities such as Kyiv, Lviv, Donetsk, Kharkiv, and Simferopol with destinations across Europe.

In 2009, Malév Hungarian Airlines, Hungary’s national carrier, entered severe financial difficulties. Although Malév would not collapse until 2012, its weakening position allowed Wizz Air to strengthen its dominance in the Hungarian market. Throughout 2009, Wizz Air expanded its operations from Budapest and added routes to destinations including Madrid, Barcelona, Rome, and various British airports.

In 2010, Wizz Air continued enlarging its network across Central and Eastern Europe. The airline increased its presence in Romania, where demand for low-cost travel was rising rapidly. Wizz Air also expanded from Poland, one of its strongest markets, launching new services from cities such as Poznań, Wrocław, Łódź, and Lublin.

In 2011 Wizz Air placed one of the most important aircraft orders in its history. In June 2011, the airline signed a memorandum of understanding with Airbus for 110 Airbus A320neo aircraft. During the same year, Wizz Air continued expanding into Balkan and Eastern European markets, including Serbia, Ukraine, and Macedonia.

In 2012 Wizz Air benefited after the collapse of Malév Hungarian Airlines on 3 February 2012. Malév’s bankruptcy immediately reshaped Hungary’s aviation market, and Wizz Air rapidly took advantage of the situation. Within weeks, Wizz Air announced several new routes from Budapest and significantly increased capacity at the airport. The airline effectively became Hungary’s largest carrier. During this year, Wizz Air also expanded its services to Israel, the United Arab Emirates, and Turkey, reflecting growing demand for low-cost travel between Eastern Europe and the Middle East.

By 2013, Wizz Air Ukraine, a subsidiary established earlier to operate within the Ukrainian market, expanded domestic and international routes from Kyiv and other Ukrainian cities. Wizz Air’s distinctive branding, featuring bright pink and purple aircraft liveries, became increasingly recognizable across Europe.

In 2014, Wizz Air announced plans for an initial public offering. On 25 February 2015 the airline officially became publicly traded on the London Stock Exchange. During this year, Wizz Air expanded further into the Middle East by launching routes to Dubai through Dubai World Central Airport, later known as Al Maktoum International Airport.

By 2015, Wizz Air became one of Europe’s fastest-growing airlines by passenger numbers. The airline launched numerous new routes connecting London Luton, Doncaster Sheffield, Glasgow, and Liverpool from multiple Eastern European cities.

The introduction of the Airbus A321 into commercial service became a major operational development because the larger aircraft allowed Wizz Air to increase capacity on high-demand routes while maintaining low costs. The airline’s first Airbus A321 entered service in November 2015.

Due to economic instability, currency depreciation, and the political crisis following the 2014 conflict in eastern Ukraine and the annexation of Crimea, Wizz Air announced on 20 April 2015 that Wizz Air Ukraine would cease operations. The subsidiary officially ended flights on 20 April 2015, after which several routes were transferred directly to Wizz Air Hungary operations.

In 2016, Wizz Air continued rapid expansion across Europe and neighbouring regions. The airline focused on developing bases including Latvia and Georgia. Wizz Air also continued expanding into the Balkans, launching routes from Tuzla in Bosnia and Herzegovina and Skopje in North Macedonia. In October 2016 Wizz Air announced a new base at Chișinău International Airport (serving Chișinău) in Moldova and a few months later in December 2016 it announced a new base in Varna, Bulgaria.

In November 2017, Wizz Air announced another major aircraft order, this time for 146 Airbus A320neo family aircraft, including A321neo models. During 2017, Wizz Air also expanded its UK operations significantly despite uncertainty surrounding Brexit, by creating a British division called Wizz Air UK. The airline bases at London Luton, taking advantage of a number of take-off and landing slots acquired from Monarch Airlines when the latter entered administration in 2017.

In January 2018 Wizz Air announced a new base at Vienna International Airport in Austria. Three Airbus 320/321 were based in Vienna to start with and operate a total of 17 new routes from the Austrian capital. As of 2018, the airline's largest hub was still at Budapest Airport with over 60 destinations in Europe and the Middle East.

The new airline received its UK operating licence and Air Operator Certificate from the UK Civil Aviation Authority on 3 May 2018. Wizz Air UK then commenced commercial operations on 17 May 2018, initially operating flights from London Luton Airport using Airbus A320 family aircraft. The airline launched new services from London Luton and other British airports to destinations across Eastern Europe and the Balkans.