The city is staging the 22nd New Zealand National Hog (Harley Owners Group) Rally - dubbed A Gathering of the Clans - as well as three contests of the Royal New Zealand Pipe Bands Association Otago Centre.
On Saturday, up to 900 Harley-Davidson motorcycles will rumble through town, and riders will be greeted by a pipe band guard of honour lining the Octagon.
Some bikers have decided to ditch their leathers for tartan kilts to mark the occasion.
The annual motorcycle rally has not been hosted by Dunedin's Deep South Kiwi Chapter since 2006.
Each year, one of New Zealand's six Hog chapters hosts the rally, which attracts about 1000 members from throughout New Zealand and overseas.
A Gathering of the Clans will bring together Harley fans from Scotland's Dunedin, various parts of the United States and most Australian states.
Jim and Chrissie Pyne, of Hastings, eloped and married at the 2008 rally in Palmerston North.
They arrived in Dunedin with Napier friends Mark and Donna Carter on Monday and spent Valentine's Day shopping at McIver and Veitch, where Mr Carter bought a new 1250cc V-Rod Muscle to go with his 1584cc Dyna Super Glide Custom.
Mrs Pyne said her wedding present, a Sportster, had been replaced by Roxy, her 1584cc Heritage Softail, which gets parked next to her husband's Road King and Screaming Eagle V-Rod.
She said attending the Dunedin rally was a trip of a lifetime.
"It's really special because I had never seen the South Island, so it's a huge adventure.
"I'm on my own bike so that's huge, and my kids are proud."
Rally co-ordinator Kevin Moylan said A Gathering of the Clans would be a boost for the southern economy.
"It's opening Dunedin up to people that have never seen it and many of them are heading through Central Otago or Southland.
"Over one third of participants are women and most are riding their own bikes.
"The atmosphere will be electric," Mr Moylan said.
McIver and Veitch co-owner Jason Veitch said hundreds of Hog members were making their way down the country to converge on Dunedin later this week.
"They're like buzzy bees to a hive. People love coming to New Zealand and for Kiwi riders the thought of riding down the South Island to a Hog rally and being able to take in Central Otago and the West Coast has massive appeal."
Public participation in the rally will peak with Saturday's Thunder Ride.
Comprising Harleys of all sizes, shapes and colours the exhibition ride is designed to excite and entertain.
"Because there are so many bikes, at any single viewing point the procession will take about 20 minutes to go past," Mr Moylan said.
Hog heaven
22nd New Zealand National Hog Rally:
Friday
• Participants gather at the Lion Foundation Arena, within the Edgar Centre, Portsmouth Dr.
• Harley-Davidson skill displays and activities in the car park.
• Harley-Davidson display at McIver and Veitch.
Saturday
• Rally riders gather behind McIver and Veitch, on Bond St, for the Thunder Ride, which begins at 10.30am.
• Ride route: Through Queens Gardens, up Lower Stuart St, through the Octagon, up Stuart St, on to Three Mile Hill Rd, into central Mosgiel, back to Dunedin on State Highway 1, finishing at the Oval.
• Chapter challenges and bikes on display at the Oval from 11.15am to 2pm.
• Evening entertainment at the Edgar Centre.
Sunday
• Activities at Edgar Centre.
