This has been the best tournament of 35-year-old Ford's career, but he proved no match for O'Sullivan, who wrapped up a 6-1 win and will bid for a seventh title at the York Barbican on Sunday.
Ford, who beat Joe Perry 6-2 in the quarter-finals, made the perfect start by winning the opening frame 68-32, but O'Sullivan responded with a break of 122 in frame two and did not look back.
He won the next five frames to complete his win, punishing Ford for his misses and completing two more half-centuries in frames four and six.
Aside from a 6-5 win over Ken Doherty in the second round, O'Sullivan has been utterly dominant, dropping no more than a single frame in any match.
"It's great that I can keep performing for the crowd because they are willing me on," O'Sullivan said on worldsnooker.com.
"The fans know I have a big heart for them. I try to play with a smile on my face and if I play a decent match it might brighten up someone's day."
The second semi-final on Saturday night was much closer, as Allen needed a final frame decider to overcome Stuart Bingham 6-5.
The Northern Irishman started in style by knocking in a break of 99 in the opening frame. However, Bingham reeled off three frames in a row, which included breaks of 81 and 45, to take control.
The pair exchanged century breaks, with Allen knocking in 104 and Bingham replying with a 132 clearance, before it was Allen's turn to win three frames on the spin to lead 5-4 and move within one of the final.
However, with the pressure on, Bingham rallied and knocks of 48 and 17 levelled up the match at 5-5 and ensured there would be a final frame decider.
Another error from Bingham proved to be his last when a safety went wrong and he left a red over a middle pocket. Allen took full advantage and cleared the table with a break of 64 to return to the final for the first time since 2011, when he lost to Judd Trump.
For Bingham, it was his third semi-final defeat in York and a place in the final at the Barbican Centre continues to elude him.