Sinn Féin leader Gerry Adams held over Jean McConville murder
Her body was recovered from a beach in County Louth in 2003.
Police said a 65-year-old man presented himself to Antrim police station on Wednesday evening and was arrested.
In a statement, Sinn Féin said: "Last month Gerry Adams said he was available to meet the PSNI about the Jean McConville case. That meeting is taking place this evening."
Mrs McConville, one of Northern Ireland's Disappeared, was kidnapped in front of her children after being wrongly accused of being an informer.
Last month, Ivor Bell, 77, a leader in the Provisional IRA in the 1970s, was charged with aiding and abetting the murder.
There have also been a number of other arrests over the murder recently.
The case against Bell is based on an interview he allegedly gave to researchers at Boston College in the US.
The Boston College tapes are a series of candid, confessional interviews with former loyalist and republican paramilitaries, designed to be an oral history of the Troubles.
The paramilitaries were told the tapes would only be made public after their deaths.
However, after a series of court cases in the United States, some of the content has been handed over to the authorities.
Informer claim dismissed The claim that Mrs McConville was an informer was dismissed after an official investigation by the Northern Ireland Police Ombudsman.
She was held at one or more houses before being shot and buried in secret.
The Disappeared are those who were abducted, murdered and secretly buried by republicans during the Troubles.
The IRA admitted in 1999 that it murdered and buried at secret locations nine of the Disappeared.
The Independent Commission for the Location of Victims' Remains was established in 1999 by a treaty between the British and Irish governments.
It lists 16 people as "disappeared". Despite extensive searches, the remains of seven of them have not been found.