Attorney General Jeremy Wright will not refer the former entertainer's sentence of five years and nine months to the Court of Appeal, a spokeswoman has confirmed.
Mr Wright's office received 150 complaints about the leniency of Harris's sentence, of which he will serve half.
In a statement, the office said Mr Wright would not refer the sentence to the Court of Appeal as "he did not think they would find it to be unduly lenient and increase it".
"The sentencing judge was bound by the maximum sentence in force at the time of the offending," it added.
"The judge made some of the sentences consecutive to reach the total sentence, but he could not simply add up sentences on individual counts; the overall sentence had to be just and proportionate to the overall offending.
"The judge was also required to take into account the age of the offender."
Harris, 84, was convicted for 12 indecent assaults last month.