A joint bid could see Hartlepool, Middlesbrough, Redcar and Cleveland, Stockton and Darlington become City of Culture in nine years.
Tees Valley Unlimited (TVU), Teesside University, the five Tees Valley local authorities, Arts Council England and other cultural groups made the recommendation as part of a broader Culture report.
The group spent the last year exploring how to enhance the Tees Valley's cultural offer and ensure it better supports the area's ambitious economic plans.
The UK City of Culture programme, inspired by Liverpool's time as European Capital of Culture in 2008, uses culture and creativity to transform communities and help grow artistic talent.
The inaugural winner in 2013 was Derry-Londonderry, and Hull has been announced as the 2017 city.
Sunderland is one of several city regions to have declared its intent to bid for the 2021 title.