Wigan chairman Dave Whelan said it is beyond his wildest dreams that the club will play in Europe next season.
The Premier League relegation strugglers reached the FA Cup by beating Millwall 2-0 in their semi-final on Saturday.
They face Manchester City at Wembley in May and, because Roberto Mancini's team are set to qualify for the Champions League, Wigan will go into the Europa League, whether or not they lift the FA Cup.
Wigan only joined the Football League in 1978 and were a fourth-tier team in 1995 when Whelan, who became a millionaire running a chain of sports stores, bought them.
At the time, the former Blackburn defender targeted the top flight but said he had never considered the possibility they would play in continental competition.
"Europe will be something new for us," Whelan told British national newspapers. "It will be fantastic. We would never have dreamed of that. Even when I arrived and said we were going to get to the Premier League, I never dreamed of Europe.
"It is somewhere you think you will never ever get to – apart from holidays in Majorca. Wigan against the biggest names in Europe... it's good, isn't it? The chances are we are going to get into Europe, which will be a whole chapter of the club's history."
Whelan, who played in the 1960 FA Cup final, will lead Wigan out against City on May 11 and told the Wigan Observer: "I don't think it has ever been done before – playing at Wembley and then leading a team out as chairman, so I might be in the Guinness Book of Records."
The 76-year-old hopes that their FA Cup success will spur them on to secure a ninth successive season in the Premier League.
"When we come out in the final, it is something that is going to be a very special day," he added. "But staying in the Premier League is massively important. We have done it for eight years now and everybody said we would last one year."