More than 20 years after an 18-year-old woman was strangled to death and buried in a shallow grave on a NSW beach, her former husband has been sentenced over the murder.

Steve Frank Fesus, 47, was found guilty last year of murdering Jodie Fesus, 18, in August 1997.

Fesus was sentenced to a maximum of 22 years prison in the NSW Supreme Court on Friday.

"He murdered his very young wife at a time of marital strain after just three months of marriage," Justice Peter Johnson told the court upon sentencing.

Despite the long-term suspicions of Jodie's family, Fesus was not arrested until 2013, after he made admissions to undercover police officers.

Fesus was jailed for a non-parole period of 16 and a half years.