Mr Gates, well known for donating large sums of money to charitable organisations and scientific research, is highly regarded everywhere, the survey by YouGov for The Times found.
Third most admired person was Russian leader Vladimir Putin, followed by Pope Francis and Indian cricketer Sachin Tendulkar.
The Queen was the most admired woman in the world, in 17th place, closely followed by Angelina Jolie and Oprah Winfrey, in a list in which women were said to be strikingly under-represented.
YouGov spoke to a total of 13,895 people in 13 countries around the world, using a mix of internet and mobile phone surveys - and concluded that if the survey had been conducted a month earlier, Nelson Mandela would have come top.
Countries taking part were Great Britain, France, Germany, Russia, the US, Australia, Pakistan, Indonesia, India, China, Egypt, Nigeria and Brazil.
Top 10 (world): 1 Bill Gates; 2 Barack Obama; 3 Vladimir Putin; 4 Pope Francis; 5 Sachin Tendulkar; 6 Xi Jinping; 7 Narendra Modi; 8 Warren Buffett; 9 Amitabh Bachchan; 10 Abdul Kalam.
Top 10 (UK): 1 Queen Elizabeth II; 2 Barack Obama; 3 Pope Francis; 4 Sir Richard Branson; 5 The Dalai Lama; 6 Desmond Tutu; 7 Stephen Fry; 8 Bill Gates; 9 Prince William; 10 David Beckham.