Learco Chindamo was 15 at the time of the killing
Mr Lawrence's killer Learco Chindamo's had appealed to have his 12-year sentence cut, but the Lord Chief Justice Lord Woolf refused his petition at the High Court on Thursday morning.
Chindamo was 15 when he stabbed Mr Lawrence to death as he defended a pupil outside St George's Roman Catholic School in Maida Vale, west London in December 1995.
He was convicted of the killing at the Old Bailey in 1996 and ordered to serve a minimum of 12 years for the murder.
The review of Chindamo's sentence came after the European Court of Human Rights ruled in December 1999 that tariffs for juvenile killers could not be set by the home secretary, but only by their trial judges or the lord chief justice.
In making his decision, Lord Woolf said he had taken sufficient account of Chindamo's age at the time of the offence to refuse any reduction in his tariff.
An adult would have been jailed for 14 years, but because Chindamo was 15, his sentence was slightly less.
Lord Woolf had received a submission from Mr Lawrence's widow Frances, in which she said that any reduction in Chindamo's sentence would have destroyed her family "twice over".
Child legal expert Allan Levy told BBC News 24, allowing victims or their relatives to make submissions to judges was a new development.
He said: "Lord Justice Woolf wouldn't take into account what she thought was the minimum period he should spend in jail, but he would take into account what was the effect on her and the family as a result of this really terrible crime."
'Mistaken identity' claim
Nigel de Gruchy from the NASUWT union said teachers would be relieved by the judge's ruling.
He said: "There is always a difficult balance to achieve between 'retribution' and 'reform'.
"While I think the majority of people would not favour locking up young murderers for the rest of their lives, a fitting punishment for crimes of this nature must be handed down for the system of justice to retain the confidence of the majority of people."
He said he was a victim of mistaken identity as another youth was wearing his jacket.
But in November 1997 the Court of Appeal dismissed his appeal against his conviction.
Thursday's High Court hearing follows the decision to free James Bulger's killers Jon Venables and Robert Thompson.
This means that the jail terms of many young killers must now be reviewed by Lord Woolf, who ruled on the cases of Thompson and Venables.