Italy will face Spain in the other semifinal match on Wednesday, with the final next weekend also to be played at Wembley.
The last time England made it to the last four of the European Championship was in 1996. But the bigger goal at this point is to duplicate the success of the 1966 England team that won the World Cup on home soil.
Kane scored on England's first opportunity in the fourth minute, using one touch to redirect a through ball from Raheem Sterling for his second goal in as many matches. The ball went in off the shoulder of goalkeeper Georgiy Bushchan inside the near post.
England also scored early in the second half after Kane was fouled about 10 seconds. A free kick from Luke Shaw set up a header from Maguire. Four minutes later, Kane got his second by heading in another cross from Shaw on a play that included a backheel pass from Sterling as England dazzled.
After failing to score in the group stage, Kane now has three goals in two matches after also scoring in the 2-0 win over Germany in the last 16.
Kane won the Golden Boot with six goals the 2018 World Cup, when England also reached the semifinals. He exited to a standing ovation at the Stadio Olimpico when he came off midway through the second half.
Henderson's goal — his first for England after a decade with the national team — also came with a header as Ukraine's defenders had no answers to England's aerial prowess.
Ukraine, which was coming off a 2-1 extra-time win over Sweden, had relied on occasional counterattacks in the first half and produced a series of chances just before the break. Otherwise, England was in control.
The Italian government had explicitly warned Britain-based England fans to stay away from the match unless they could prove they had observed five days of quarantine since arriving.
Still, there were clearly more England supporters than Ukraine fans inside the partially filled stadium. But a pocket of yellow-clad Ukraine fans made plenty of noise by banging on drums and chanting.
Because of the pandemic, the Olimpico could only be 25% full with about 16,000 fans.
Ukraine residents also faced restrictions for travel to Italy.
