Works include a pedestrian and cycle bridge across the A63 and extensions to the city's art gallery and theatre.
The bridge will cost £11.5m and will link the city centre with Hull's waterfront, which is being redeveloped.
The Ferens Art Gallery will get a £4.5m facelift ahead of it hosting the Turner Prize in 2017.
Labour councillor Sean Chaytor, chairman of Hull City Council's planning committee, said the bridge was "essential in working towards improving connectivity between two core areas of the city".
"We hope that the work to start the bridge construction can now get under way for early next year in order for it to be ready by Easter 2017," he said.
Hull was awarded the title of City of Culture in November 2013, beating competition from Swansea, Leicester and Dundee.
The year-long event takes place every four years and is awarded by the UK government with the aim of helping tourism and the economy.

The roof of the building on Main Road in Otterbourne, near Eastleigh, collapsed during the blaze, which broke out at about 03:30 GMT.
No injuries were reported at the site, which also contains workshops and offices. An investigation is under way.
The neighbouring convenience store, which was saved, is due to reopen later.
Ty Whitlock, commanding officer at the scene, said: "When we pulled up we were faced with flames coming out of the roof, coming out of the glass doors and windows and obviously huge amounts of smoke coming from the eaves."
A number of building projects planned for Hull's year as UK City of Culture in 2017 have been approved by the council.
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Up to 40 firefighters have been tackling a large fire which destroyed a garage in Hampshire.