In Iron Range National Park, there are two walks. There is a shorter one in the bush on Chili Beach, and then there is a longer one that follows the Old Coen Track. It starts at the Rainforest Camping ground and goes through some beautiful tropical rainforest.
Lakefield National Park
Lakefield National Park is huge so considering its size there is very little bushwalking there. There are, however two tracks - a 7km one near Hann Crossing Campground, and a 4km one near Kalpowar Campground. It's a great national park for bird and wildlife watching.
Mt Cook National Park
Mount Cook is just south of Cooktown. You can find the start of the track by following the signs in the southern streets in the town. It is a reasonably steep walk in parts, and takes a good few hours, so be prepared, and time it to the cooler parts of the day.
Cedar Bay National Park
Cedar Bay National Park is south of Cooktown, along the Rossville Bloomfield Road that is north of the famous Bloomfield Road. There are 23km of bushwalks, to Home Rule Falls, and to the bay itself. This is the only way to get to the bay except waterways.
Mt Sorrow Walk (Daintree)
This walk starts just south of the Bloomfield Track, and north of Cape Tribulation. It is a steep walk, suitable for fit bushwalkers, and takes many hours, so be prepared and start early in the morning to allow a lot of time. The first half of it is not too bad, but the second half is quite steep.
Mowbray National Park
Mowbray National Park is next to the Black Mountain Road, south of Julatten and north of Kuranda. Its most famous long bushwalk is the Bump Track which you can access near the northern end of the Black Mountain Road. It is a long walk to coastal lowlands.
Davies Creek and Dinden National Parks
There are a few good four wheel drive and bushwalking tracks in Davies Creek and Dinden National Parks east of Mareeba. Some of the better ones are the challenging Ridge Trail Walk and Kahpahlim Rock Track, reached from the road to Davies Creek.
Chillagoe Caves National Park
Chillagoe is inland from Mareeba, in Cairns Outback. Outside the town is Chillagoe Caves National Park. There are some great limestone caves to visit, as well as some walking tracks. The longest one is 10km, but it's an easy bush walking track.
Long Walks around Cairns
Barron Gorge National Park stretches all the way from Cairns to Speewah and Kuranda. You can drive to the gorge, or catch a train through the park to Kuranda, but what is less known is that there are extensive walking tracks in that park - you could walk from Cairns to Speewah and Kuranda.
And there is more south of Cairns.
Wooroonooran National Park
Wooroonooran National Park protects Queensland's highest mountain, Mt Bartle Frere. There are two long walks: the 19km Goldfields Track from Babinda Boulders to Goldsborough Valley; and the 15km Bartle Frere Trail that climbs the summit.
Boulders are beautiful granite boulders in Wooroonooran National Park
south of Cairns, near the small town Babinda.
Misty Mountains is a network of long bush walking tracks that go through a few national parks. Its northern walks are in the southern end of Wooroonooran NP, just south of Palmerston Highway. Others are reached from Tully and South Johnstone.
Hinchinbrook Island is just off the shore of Cardwell that is half way between Cairns and Townsville. There is a three day walk, called Thorsborne Trail from the southern to the northern end of the island. The walk is so popular it gets booked out for months ahead.
Girringun National Park
Girringun is a huge national park with many different sections west of, and around Cardwell. There are some serious and half serious walks such as the Wet Tropics Great Walk from Wallaman Falls to Blencoe Falls; and the Dalrymple Gap Track in Abergowrie.
Long Walks around Townsville
Townsville doesn't seem like a place to bushwalk, but there are some long walks in Town Common Conservation Park (great for bird watching too); as well as in the Mount Elliott section of the Bowling Green Bay National Park south of the town, such as the 16km Alligator Creek Falls Track.