After a tricky start for both players, Selby grew into the match and took control in the third frame to eventually go on courtesy of runs of 76, 84, 132 and 69.
Selby, who ousted Ronnie O'Sullivan in the quarter-finals, will face Jack Lisowski, who beat defending champion Mark Allen in evening's semi-final tie.
World Championship
'Phenomenal Selby stopped Murphy playing in final' - White
04/05/2021 AT 09:04
The afternoon match started off with plenty of nerves on show, highlighted by Selby and Gilbert's poor break offs in the opening two frames. Both were cagey affairs with the world number six edging them.
But it was in the third where Selby showed his quality, registering a break of 76 before an 84 clearance in the fourth put him in a commanding lead.
Gilbert at least got on the scoreboard with breaks of 64, 66 in the fifth to make it 4-1, but it was Selby who would go on to take the sixth with a total clearance of 132.
The seventh was more tightly contested but Selby emerged victorious with a break of 69.
"I thought I played quite well after the first two frames," Selby told Eurosport post-match.
The first two frames were probably like watching two guys down the social club!
"As the tournament has gone on I feel I've played a bit better. I keep going in and out of focus. I'm focussed until I think I've won the frame and then I slack off which I shouldn't do.
"I could have finished with two centuries [in the final frame] so I should have had the motivation."
World Championship
'He broke me' - Emotional Murphy on loss to 'super-granite' Selby
04/05/2021 AT 08:07
World Championship
'He hid round the corner!' - Selby reveals bizarre distraction on final black
03/05/2021 AT 22:44