Talking trees are a form of sapienttrees in mythologies and stories.
According to Greek mythology, all the trees in the Dodona (northwestern Greece, Epirus) grove (the forest beside the sanctuary of Zeus) became endowed with the gift of prophecy, and the oaks not only spoke and delivered oracles while in a living state, when built into the ship Argo the wood spoke and warned of approaching calamities.
The rustling of the leaves on an Oak tree was regarded as the voice of Zeus.
The Indian Tree of the Sun and the Moon: Told the future. Two parts of the tree trunk spoke depending on the time of day; in the daytime the tree spoke as a male and at night it spoke as a female. Marco Polo is said to have visited this tree.
The weeping Date palm tree: The Prophet Muhammad, when delivering his sermons used to stand by or lean on a date palm tree. When a pulpit was built elsewhere and Muhammad started to give his sermon from the pulpit, the tree began to cry like a child. Muhammad then descended from his pulpit and consoled the tree by embracing it and stroking it. The Prophet said, "It was crying for (missing) what it used to hear of religious knowledge given near to it." This incident is recorded in the authentic IslamicHadith traditions and is said to have been witnessed by everyone present at the congregation.
Oracular Trees are sometimes attributed with the ability to speak to individuals, especially those gifted in divination. In particular, Druids were said to be able to consult Oak trees for divinatory purposes, as were the Streghe with Rowan trees.
In the Old English poem Dream of the rood, a tree talks about being cut down and used as the cross on which Christ was crucified.
In Ireland, a tree may help a person look for a leprechaun's gold, although it normally does not know where the gold is.
In Dorothy of Oz, there are a group of Talking Trees that grow on the banks of the Munchkin River in Gillikin Country and have known Wiser the Owl. Upon the advice of Wiser, Dorothy, Scarecrow, Tin Man, and Cowardly Lion had to convince the Talking Trees their to donate their limbs in order to make a boat that can take them to Glinda. The Talking Trees agree to help Dorothy and also help to coordinate the construction of the boat that became Tugg (who then began to speak after Dorothy used paint made from water and berries to make a face for Tugg). Besides taking Dorothy and her friends to Quadling Country, Tugg also traveled the Munchkin River where he would later tell the Talking Trees what he has seen on his journey.
In The Legend of Zelda series, the Great Deku Tree is a massive sentient tree who helps Link in his quests, and also serves as the guardian of the forest/earth.
In the Fallout video game series, Harold is a character who has, through viral mutation/radiation poisoning, become symbiotically combined with a tree. Harold is a recurring character in the series, and begins as a mutated human with a small tree growing out of his head, but later resembles a fully grown tree with a wooden human form embedded in it.
In Avatar, The Tree of Souls, besides being a connection to Eywa, also works as a way for her to directly interact with the world through the seeds of the tree. The tree has the capability to connect directly to the human nervous system, despite humans lacking a queue. The roots of the Tree of Souls are capable of initiating a neural link with the Na'vi, like with the Tree of Voices. This allows all of the Na'vi to unite as one. 
The Yaqui have a legend of a talking tree. The tree told of the Christian God and the priests who would soon arrive to teach the people new beliefs and new ways.
Artist Théodore Rousseau (1812-1867) is quoted as saying "I also heard the voices of the trees … whose passions I uncovered. I wanted to talk with them … and put my finger on the secret of their majesty."
In the game Golden Sun, the player encounters Tret and Laurel, talking trees who guard Kolima forest.