He provided the voice of the title character in ParaNorman (2012) and appeared in Dawn of the Planet of the Apes (2014), X-Men: Apocalypse (2016), Alpha (2018), and Dark Phoenix (2019).

In 2021, Smit-McPhee garnered critical acclaim for playing a troubled teenager in Jane Campion's western film The Power of the Dog.

Smit-McPhee was born on 13 June 1996[1] in Adelaide, South Australia, the son of Sonja Smit and Andy McPhee.

[2] At age 16, Smit-McPhee was diagnosed with ankylosing spondylitis, a degenerative form of arthritis which causes vertebrae in the spine to fuse and can lead to chronic pain and loss of vision.

[3][4] While filming The Power of the Dog, his vision was impaired in his left eye due to a severe cataract related to his condition.

He plays 17-year-old Thomas "Tolly" Johnson, who pretends to be older so that he can enlist with his brother Bevan and ends up fighting at Gallipoli in the campaign that helped create the Anzac legend.