Jackson was called to the Bar by the Inner Temple in 1978 and became a Queen's Counsel in 2000. He was subsequently appointed as a Recorder in 1998, a Deputy High Court Judge in 2003 and a High Court Judge with effect from 1 October 2010. Referring to his work as a barrister, Chambers & Partners described Jackson as a "master tactician stalks his prey in a very subtle, understated manner... He plays to win and does so more often than not," while Legal 500 called him "one of the most authoritative children silks around."
In February 2011 Jackson made a landmark ruling allowing journalists to attend hearings in the Court of Protection in a case about an autistic man who had been kept away from his home and family by a local authority, the London Borough of Hillingdon. Jackson also agreed to allow the news media to identify all parties in the case. Previously, the court had been widely criticised in the media for being able to make crucial rulings without public scrutiny.
Poppi Worthington case
In January 2016Judge Jackson issued a ruling which appeared at variance with the findings of police investigation which had resulted in no prosecution. Although there had been no prosecution the Judge found that the father had on the balance of probabilities abused the baby before her death. Judge Jackson also criticised the Police and Social Services.
Judgment in plain English
In September 2016 Jackson was praised for rephrasing the entire judgement in the case of Lancashire County Council v M and Others into a 17-page document using simple phrases and emojis with the intention that the children involved would be able to read and comprehend it themselves. The ruling is thought to be the first in English legal history to incorporate an emoji, or web symbol, or to explain a point of evidence.
Cryogenically frozen girl
In October 2016 Judge Jackson ruled on the case of a 14-year-old girl dying of cancer. The judgment was technically that the mother should be allowed to decide about disposal of her body on death. The Judge visited the girl in hospital, at her request, shortly before her death.
Parental access to ultra-Orthodox Jewish children
Judge Jackson ruled 'with real regret' that the Court could not order parental access for a transgender parent of ultra-Orthodox Jewish children
Judgment in form of letter to a child
In July 2017 Jackson delivered a judgment in a case about the residence and citizenship of a teenage boy. He presented it in the form of a letter written directly to the boy, explaining why he was deciding the case in the way that he was.
