Mr Hichilema defeated his main rival, the outgoing President Edgar Lungu, by more than a million votes.
But who is the new president? And why has he succeeded after years of failure?
Mr Hichilema, 59, has described himself as an ordinary “cattle boy”, who herded his family’s livestock in his youth before going on to become one of Zambia’s richest men.
The president-elect and leader of the United Party for National Development (UPND) is widely referred to as HH. He was born into humble beginnings before managing to get a scholarship to the University of Zambia, and later graduated with an MBA degree from the University of Birmingham in the UK.
He went on to make a fortune in finance, property, ranching, healthcare and tourism.
He has used both aspects of his background to appeal to voters.
He told voters that they needed a successful businessman to understand how to get the economy moving in the copper-rich nation, where there is high unemployment. He also used his agricultural roots to appeal to the country’s farmers, saying he could turn Zambia into a food basket for the region.
But it was Mr Hichilema’s ability to connect with younger voters that was perhaps the biggest factor in his success. More than half of the seven million registered voters in Zambia are under the age of 35. Around one in five of them are unemployed.
The governing Patriotic Front (PF) swept to power in 2011 on the promise of “less taxes, more money in people’s pockets and more jobs”. But this did not materialise for many young people and they turned out in their millions for Mr Hichilema.
One of the ways he connected with young people was through social media. This was not the first election that Mr Hichilema attempted to use the likes of Facebook and Twitter to connect with voters, but he has recently upped his game. (BBC)