Continuity mistake: When Sammy first offers the drink to Diana (in a close up), Diana takes the mug in her left hand. Just before the camera switches to a long shot, Diana switches the mug to her right hand. In the long shot, Diana still has the mug in her left hand and she sets it on the wall to her left. The camera switches back to a close up and Diana again has the mug in her right hand. When Steve asks her to dance, Diana again sets the mug down on the wall, this time to her right.
Continuity mistake: At the end after the massive explosion on the runway, two German soldiers get up unscathed and remove their gas masks. They suddenly appeared, as no one else was there, only Diana, and they are only a few feet away from the crater.
Other mistake: Field Marshal Haig is listed in the credits as Field Marshall Haig. This spelling (with two Ls) is only ever a surname, not a rank or job title.
Factual error: When Steve gets dressed after bathing in the pool he zips up his fly. The film is set during the First World War. The zip was not used on clothing until 1925 and did not become common on flies until long after that.
Factual error: The word "intel", used several times, is first recorded in 1961. It certainly wasn't in use in 1918.

Continuity mistake: When Diana get the photo at the start, there's a clipboard beside the case when she opens it, but from another angle there's nothing there.
Continuity mistake: Just before Diana uses her bracelets to repel Antiope's attack, the sun changes between shots.
Continuity mistake: While Diana and Steve are lying on the boat next to each other, the space between them changes from shot to shot.

Continuity mistake: As Diana is translating in the General's office, one of the buttons on her coat is undone/missing. As she approaches his desk, it's suddenly visible on her coat where it should be.
Character mistake: While posing as Steve's driver, Sameer refers to him as a colonel. He is actually wearing captain's epaulettes.
Continuity mistake: At the end when Diana is moving through the crowd approaching the memorial wall, the Scottish sniper is behind her. In the next shot when she turns around, he is again behind her.
Character mistake: Chief says the poison gas should be flammable because it's hydrogen-based. Hydrogen is the most common element in the universe, and there are plenty of non-flammable substances that contain hydrogen - the most notable of which being water.
Suggested correction: Hydrogen is explosive in air at concentrations greater than about 4%.
Pure hydrogen is flammable, yes. However a chemical compound that contains hydrogen would not necessarily be explosive, or even flammable. As the original mistake stated, water contains hydrogen and is not flammable. Whilst other hydrogen-containing compounds are flammable (such as hydrocarbons), the presence of hydrogen alone is not the reason for its volatility.
Continuity mistake: While the sniper is shooting at the square, Diana loses her shield with the cannon shot but few moments later she has it back again to smash the tower.
Continuity mistake: Wonder Woman is fighting the soldiers on the second floor in the village, after she retrieves her shield. Her sword goes from properly in her hand, to being held by the blade, to held by the blade upside down, but when she looks up, just before going through the window, the blade is normal again. (01:18:05)
Continuity mistake: When Diana and Steve are held at gunpoint in the alley, the gun's hammer is drawn back and in the next shot it is in the resting position. (00:53:15)
Continuity mistake: When Antiope and Diana see the god killer sword, Antiope's hands are around Diana's shoulders but in the next shots they have moved.
Continuity mistake: At the beginning while Diana as a child is running among the people, a girl in gray is walking differently between shots.

Continuity mistake: After Diana crashes through the window, there are various bits of wooden debris on the floor in front of her. In a wider angle those bits have vanished.
Factual error: When the German Empire's soldiers are attacking Themyscira in the Mediterranean, one of their rowboats has the ship's name "Schwaben" printed on its side. The "Schwaben" at the time of the movie was a barge on patrol duty on Lake Victoria in back-then German East Africa.
Suggested correction: Since a lot of elements of WWI are different in this universe, a ship that is out of place is not strange.
Continuity mistake: When Steve Trevor is at the Ottoman empire, he is beside a biplane that look like a British one. In the background to his right are a series of Fokker EIIIs, the next shot he's turning to his right, just besides a Fokker... and the British biplane has disappeared. (00:24:23)