The 28-year-old former Bournemouth, Portsmouth and Leeds United centre-back has signed a three-year contract with the Addicks.
Pearce made 33 appearances last season as the Latics won the League One title and becomes Charlton's seventh signing of the summer transfer window.
"He's an absolute warrior," boss Russell Slade told the club website.
Find all the latest football transfers on our dedicated page.

Some reports put the number even higher. The roof of the church caved in on worshippers who had gathered for the ordination of a bishop on Saturday.
Those inside the Reigners Bible Church included Akwa Ibom state governor Udom Emmanuel, who survived the disaster.
The church was still under construction and workers had rushed to complete it for the ordination, witnesses said.
Mr Emmanuel said there would be an investigation into whether safety standards had been compromised.
Eyewitnesses told Reuters news agency that they had seen more than 100 bodies at the local morgue.
Etete Peters of the University of Uyo Teaching Hospital told the AP news agency that at least 160 people had been killed.
Many more victims may have been taken to private mortuaries across Uyo, AP adds.
President Muhammadu Buhari has expressed "deep sorrow" over the incident.
An unnamed survivor quoted by Nigeria's Channels TV said: "Suddenly, the roof fell on worshippers. The governor was quickly rescued. But others were not that lucky."
Building collapses are relatively common in Nigeria, mainly due to the use of sub-standard materials and the violation of building regulations.
In 2014, scores of people were killed when a church hostel belonging to a Nigerian TV evangelist collapsed in the city of Lagos.

A report due to go before the authority's cabinet on 15 July is proposing to make the cuts to cope with "a significant funding shortfall".
The proposed cuts would see 195 job losses, 47 of those posts are already vacant according to the authority.
The plans could also see the closure of Woodside Lodge care home and cuts to services for those with learning disabilities.
A library review is also under way with a formal consultation for both service users and affected staff expected in the autumn.
Deputy leader, Labour's Stephen Barnes-Andrews said: "We have a clear vision for where we want to be in 2017, but to get there we have to change the way we work and make some difficult decisions.
"Any changes we make will be focused on delivering the best possible outcomes for our residents."
The report highlights the likely gap that will be faced for 2015-16, is estimated at more than Â£30m.
Councillor Royston Smith, leader of the Conservative group, said: "This announcement is betrayal. A betrayal of all those workers who were promised their jobs were safe with Labour and a betrayal to all those people who voted Labour after being promised services would be protected.
"In two years in office Labour has refused to share services and accommodation, outsource to protect services and share management roles with other public sector bodies.
"There is so much more that could have been done before sacking hundreds of workers, cutting support to disabled residents and closing care homes."
In a statement, Unite described Mr Smith's claim of betrayal as "a joke" and said it was the government that was "betraying the people of Southampton by slashing funding, forcing councils to do their dirty work".
It added it was opposed to any cuts that affect jobs and services to the vulnerable.
"Job losses and outsourcing is not the answer," it said, adding: "If cuts carry on at this rate we fear there will be no council left by 2020."
It added the joint unions had "defeated" cuts to the service in 2012 and would support campaigns against these new cuts.
League One club Charlton Athletic have signed defender Jason Pearce from Wigan for an undisclosed fee.
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At least 100 bodies have been recovered from a church that collapsed in the south-eastern Nigerian city of Uyo.
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Budget cuts at Southampton City Council could result in nearly 200 job losses.