He may be 85 but trucking magnate Lindsay Fox knows how to have fun on the high seas

The 85-year-old billionaire business tycoon has set tongues wagging with the fun theme for one of his parties on board a luxury liner.

Lindsay Fox is hosting a pyjama party on one of the nights of the cruise.

When one of Australia’s richest men decides to throw a pyjama party no one is popping down to the local sales rack at the closest discount store to pick up a set on special.

Business tycoon and philanthropist Lindsay Fox is setting sail from New York to Montreal with a boatload of mates in the coming weeks to mark his 85th birthday.

While there are a number of events for guests to enjoy on the private charter, the one that has had Melbourne talking is the PJ party.

The pyjama party is apparently not Fox’s actual birthday function, rather it is understood to be a themed get together on one of the nights of the cruise.

“Lindsay loves a theme,” an insider said.

“What a good way to get everyone to relax and have some fun.”

Lindsay Fox with his wife Paula will be joined by a boatload of mates for the birthday celebrations. Picture: Aaron Francis

Certainly some guests are taking the dress code seriously with custom made ‘nightwear’ being whipped up for the soiree by highly regarded tailors.

The billionaire’s pyjama party was a talking point at several up-market events in Melbourne this week – particularly how literally to interpret the dress code.

No doubt plenty of guests will be stocking up on Melbourne’s pyjama king Peter Alexander’s famous lounge wear sets.

To mark his milestone birthday Fox has chartered a luxury liner, similar to what he did for his 80th birthday.

The theme for that celebration was that it was his ‘conception party’.

Fox was a bit difficult to track down yesterday, so unfortunately we are yet to hear from the birthday boy himself on what else is in store for his cruisers.