The League Two club have confirmed Cole, who won five Premier League titles and a Champions League during his playing career, has taken up a part-time role at the club.
Macclesfield manager Campbell played alongside Cole with England and the two were also team-mates at Portsmouth in the 2006-07 season.
"Macclesfield Town are delighted to confirm that former Manchester United and England striker Andy Cole has joined the club's coaching staff on a part-time basis," the club confirmed on their official website.
"We would like to welcome Andy to Macclesfield Town and wish him every success during his time with us."
Cole scored a total of 289 goals across his career and is the third-highest scorer in Premier League history, behind only Alan Shearer and Wayne Rooney.
Cole spent a total of seven seasons with United, winning a total of nine trophies including the aforementioned Premier League and Champions League successes.
Campbell took his first managerial post in November with Macclesfield bottom of the League Two table and five points adrift of safety at the time.
He has since collaborated in a coaching capacity at a variety of different teams, including MK Dons, United and Huddersfield Town.
Macclesfield remain in the relegation zone but have won three of their last seven games under Campbell and have moved up to 23rd, three points behind Yeovil in 22nd.