Expressway S5 or express road S5 () is a Polish highway which runs from Grudziàdz (connecting to motorway A1 towards Gdaà Âsk) through Poznaà  (partial concurrency with motorway A2) to Wrocà Âaw (connecting to motorway A8).
The expressway was constructed between 2009 and 2022. Its total length is about .
In 2015, it was announced that S5 will be further extended from Grudziàdz to Ostróda (connecting to S7). In 2019, an extension from Wrocà Âaw to Bolków (connecting to S3 near the border with Czech Republic) was added to the plans. Both extensions are intended to be completed as part of the road construction plan until 2033, which will increase the total length of the expressway to about .
The construction of the road received higher priority after Poland was selected as one of the hosts of the UEFA Euro 2012 championship, since it would have provided a direct connection between three of the four Polish cities hosting matches: Poznaà Â, Wrocà Âaw and Gdaà Âsk. However, plans to finish the road before the championship were proven too optimistic and only a section between the A2 motorway and Gniezno (35 km), opened on 4 June 2012, was completed by that time. This fragment of S5 serves as the eastern bypass of Poznaà Â.
In October 2015, the planned future route of the expressway has been extended from the Nowe Marzy junction (near Grudziàdz) to Ostróda. In November 2015, contracts were signed for the Gniezno-Grudziàdz section, a total of about 150 km. In May 2017, the continuation of the S5 from the end of the eastern bypass of Poznaà  to just north of Gniezno opened to traffic, thus diverting most transit traffic away from Gniezno itself. In 2019, the planned route was extended from Wrocà Âaw to Bolków. In 2022, the last section of the original route was completed.