The cost-cutting move will see hearings moved to Preston Magistrates' Court and matters dealt with through new 'listing arrangements' from April 1.
Officials for the Ministry of Justice (MoJ) say the money saved will be 'reinvested into modernising the justice system'.
The closure of the Saint Thomas's Road court was announced last year following a consultation but until today no date had been released.
Chorley's Sir MP Lindsay Hoyle reacted to the news, which he had campaigned against, on Twitter, saying: "Terrible news for local justice.
"Minister says closures make business sense as 41% of courts operate at 50% capacity - slash the number of bobbies on the beat in Lancashire by 750+ then court use will drastically fall I suppose."
Figures released by the MoJ show Chorley Magistrates' Court sat for less than half of its available hours.
Preston will benefit from an additional tribunal hearing room, meaning that the work of Chorley can be accommodated.
HMCTS will work with local people to ensure a smooth transition.
A video link is already available in all courts for vulnerable victims and witnesses.
At the time of the closure announcement, Lord Chancellor David Gauke said: "All money raised from the sale of these buildings will be reinvested into the justice system, and we want to reassure communities that those affected by closures will have access to alternative courts.
"We must ensure we use public money effectively and make decisions in the best interest of the wider justice system."
All Magistrates Courts were assessed on the basis of ensuring access to justice, delivering value for money and the ability to deliver efficiency in the long term.