Microsoft co-founder Bill Gates and his wife Melinda Gates are the world's richest couple holding a net worth of $85.7 billion together, according to a report.

Bill Gates, who continues to be the world's richest person for 16th time this year, had married Melinda in 1994, when she was a Microsoft employee.

Net worth of Bill Gates, who was one of the co-founders of Microsoft in 1975, stood at $79.2 billion in 2015, up from $76 billion last year, according to Forbes.

The couple had started Bill & Melinda Gates Foundation in 2000, which primarily aims at improving healthcare and reducing poverty across many countries.

"In 2010, the couple joined billionaire investor Warren Buffett to form the Giving Pledge -- a campaign to spur the world's wealthiest individuals to commit the majority of their wealth to philanthropy," The Economic Times quoted Wealth-X, the global wealth intelligence firm, as saying.

Spanish retail business magnate Amancio Ortega Gaona and his second wife, Flora Perez, occupied the second spot in a list of world's wealthiest couples. Their combined net worth stood at $70.7 billion.

The couple got married in 2001 and Flora is now working as the vice president of the Amancio Ortega Foundation.

The "Oracle of Omaha" Warren Buffett of Berkshire Hathaway and his wife Astrid Menks were ranked at the third position.

Facebook co-founder Mark Zuckerberg and his 30-year old wife Priscilla Chan are currently the youngest couple on the Wealth-X list, standing at ninth position. "They boast a combined net worth of $38.5 billion. The couple met at Harvard in 2004 and were married in a low-key, simple wedding ceremony in their Palo Alto home in 2012," the report said.

Other Wealthiest Couples in the List:

Rank Wealthiest Couple Net Worth
Fourth David and Julia Koch $47.5 billion
Fifth Charles and Elizabeth Koch $47.4 billion
Sixth Wang Jianlin and Lin Ning $40.7 billion
Seventh Jeff and Mackenzie Bezos $39.8 billion
Eighth Bernard Arnault and Helene Mercier $38.7 billion
Tenth James and Lynne Walton $36.2 billion