Hughes killed father-of-two Douglas Graham in a car accident near Coventry in November 2003 while driving home from a post-match drink and was jailed the following August.
He also caused serious injuries to another man, Albert Frisby, and fled the scene of the accident on foot to avoid a breath test.
But a remorseful Hughes said: "I wish to make some comment about the circumstances that resulted in my imprisonment three years ago.
"I'm acutely aware of my actions, which resulted in the death of one person and serious injury to others.
"I only wish I could turn back the clock.
"Although I have served the sentence laid down by law, I know that nothing I can do or say will change what has happened.
"In going some way to facing my responsibilities I have met with a relative of the man who died, and what was said will always remain a private and personal matter.
"For different reasons, I think we were both glad that the meeting occurred.
"This is the first time I've been able to make a public apology for my actions and I now hope for an opportunity to rebuild my life.
"After this press conference today, I do not intend to discuss or make comment about the events which led to my imprisonment.
"I have made this decision, not out of protection for myself, but with regard to the privacy and respect for the families involved.
"I made dreadful mistakes and decisions that will live with me for the rest of my life.
"It also greatly affected my immediate family, including my wife and children and I will never forgive myself for this."
Hughes revealed he had chosen Oldham ahead of several other clubs to resurrect his career because of the support they had shown both him and his family.
He said he intended to move his family to live in the Oldham area.
Hughes added: "Having spoken to club officials and the management team, I've never been in any doubt that this was the club I wanted to play for.
"The club has also been extremely understanding with my family and we intend to live in the area as soon as possible.
"I'm eager to get going and know that difficulties will lie ahead.
"That will only spur me on to do well and, given my experience in the higher leagues, I'm hoping to contribute significantly in helping Oldham to get promoted."
Hughes also revealed he was keen to work with the local community to help show youngsters the dangers of alcohol.
He added: "While it's not part of my contract, it has always been my intention to do some community work centred on the mistakes I have made, in the hope that it can go some way to preventing another tragedy occurring.
"I truly want to do this and will be visiting schools, colleges and other football clubs to speak to young people.
"If by doing this I help or persuade people not to make the mistakes I have made, I will be a happier person.
"I'm prepared to take responsibility for anything that comes my way during my re-entry into the football world.
"Out of respect for those families concerned, including my own, I would ask that I be allowed only to comment in the future about football matters and rebuild my life around the job I do.
"To the Oldham fans, I'm here to help the club achieve its ambitions and hope you can help along the way."