Robert Herjavec (Croatian: [xěrjaːʋet͡s]; born September 14, 1962) is a Croatian-Canadian businessman, investor, and television personality.

Herjavec founded BRAK Systems, a Canadian integrator of Internet security software, and sold it to AT&T Canada (now Allstream Inc.) in 2000 for $30.2 million. In 2003, he founded The Herjavec Group, now one of the largest information technology and computer security companies in Canada, with over $200 million in annual revenue. He has been a panelist and investor on several versions of the business reality series Dragon's Den, including the Canadian CBC series Dragons' Den, the American ABC's version of the series Shark Tank, and from 2023, on the Australian Network 10 version also titled Shark Tank. He has also written books on advancing in business.

Herjavec received the 2012 Ernst & Young Ontario Entrepreneur of the Year Award for Technology and the 2012 Queen Elizabeth II Diamond Jubilee Medal by the Governor-General of Canada for Outstanding Service to Canada.

Herjavec was born in 1962 in Varaždin, SFR Yugoslavia (present-day Croatia), and spent his early childhood in Zbjeg. In 1970, when Herjavec was eight, the family left the country, which had previously jailed Herjavec's father, Vladimir Herjavec, for speaking out against the governing system. According to Herjavec, "He’d drink a little too much and then say bad things about Communism, and got thrown into jail 22 times for being an anti-Communist." Herjavec's family arrived in Halifax, Nova Scotia, with a single suitcase and only $20. The family eventually settled in Toronto, where they lived in a family friend's home basement for 18 months. For Herjavec, who spoke no English, the transition proved difficult. Having grown up on a farm and raised by his grandmother among neighbours with similar lifestyles, he found himself in a much poorer economic class than his neighbours.

Herjavec's father got a job in a factory in Mississauga, making $76 a week. Herjavec cites his father, whom he describes as "a really, really tough guy", as a significant influence in his life. Herjavec has told a seminal memory of his, when he came home one day to complain to his mother that his classmates were making fun of him. His father, who used to walk to work to save money on bus fare, came home, and when he heard what his son described, instructed his son never to complain, which became a guiding principle in Herjavec's life, one which he says sparked his sense of courage. Another influential episode in his youth came when a traveling salesman persuaded Herjavec's mother to buy a vacuum cleaner for $500, which was seven weeks' salary. As a result, Herjavec swore his family would never be taken advantage of again.

In 1984, Herjavec graduated from New College at the University of Toronto with a degree in English literature and political science. To make a living and help support his family, Herjavec took on various minimum wage jobs in the 1980s, such as waiting tables, delivering newspapers, retail sales, and debt collection.

In the mid-1980s, Herjavec worked in several productions as a third assistant director, including Cain and Abel and The Return of Billy Jack. He was a field producer for Global TV of the 1984 Winter Olympics in Sarajevo.

Looking for work between productions, Herjavec applied for a position at Logiquest selling IBM mainframe emulation boards. He was not qualified for the position but convinced the company to give it to him by offering to work for free for six months. To pay the rent during this "free" period, Herjavec waited tables. He eventually rose in the ranks to become General Manager of Logiquest. In 1990, after being fired from Logiquest, he founded BRAK Systems, a Canadian integrator of Internet security software, from the basement of his home. BRAK Systems was sold to AT&T Canada (now Allstream Inc.) in March 2000 for $30.2 million. He then became Vice President of Sales at Ramp Network, which was sold to Nokia for $225 million.