Rudman, who won the title for the first time in her career, came in joint third on the day at the final event of the season at the Canada Olympic Park.
It is the first time for 10 years that Britain has boasted a skeleton world champion, after Alex Coomber last won the title in 2002.
“For the past three years I have been second in the World Cup series and each time it has been down to the final race to decide the overall winner,” said Rudman.
“And this season all I had to do was finish ahead of Marion Thees, who was seven points in front of me, in Calgary and I feel so proud to have done that.
“The World Cup title is what I have been after since starting the sport and to me the overall World Cup title is the most prestigious title to win in skeleton.”
Yarnold edged out German former world champion Anja Huber to claim gold while two-times European champion Rudman was tied for third with Amy Gough of Canada.
It was Rudman's third podium of the season, propelling her to 1507 points in the overall standings, head of Germany's Marion Thees with 1458 and newly deposed champion Anja Huber on 1443.
In the men's event, Martins Dukurs claimed the World Cup title with his seventh victory of the season.
The Latvian won the race ahead of Alexander Tretiakov from Russia and Germany's Frank Rommel in third.
It is the third consecutive season Dukurs has won the title. Rommel ends the season in second place with Dukurs' brother Tomass, fourth in Calgary, finishing in third overall.
1 YARNOLD, Elizabeth GBR 1:55.93 + 0.00
2 HUBER, Anja GER 1:56.47 + 0.54
3 RUDMAN, Shelley GBR 1:56.57 + 0.64
3 GOUGH, Amy CAN 1:56.57 + 0.64
5 HOLLINGSWORTH, Mellisa CAN 1:56.70 + 0.77
5 CHAFFER, Lucy Katherine AUS 1:56.70 + 0.77
7 REID, Sarah CAN 1:56.71 + 0.78
8 UHLAENDER, Katie USA 1:56.87 + 0.94
9 O'SHEA, Anne USA 1:56.99 + 1.06
10 THEES, Marion GER 1:57.20 + 1.27
1 DUKURS, Martins LAT 1:51.88 + 0.00
2 TRETIAKOV, Alexander RUS 1:52.56 + 0.68
3 ROMMEL, Frank GER 1:53.28 + 1.40
4 DUKURS, Tomass LAT 1:53.38 + 1.50
5 DALY, John USA 1:53.41 + 1.53
6 NEILSON, Eric CAN 1:53.46 + 1.58
7 CHUDINOV, Sergei RUS 1:53.48 + 1.60
8 KROECKEL, Alexander GER 1:53.57 + 1.69
9 ANTOINE, Matthew USA 1:53.58 + 1.70
10 GASSNER, Alexander GER 1:53.61 + 1.73