Jill Mortimer received 15,529 votes in a win which has been described as a “shattering” result for Labour.
Prime Minister Boris Johnson was also in Hartlepool on Friday afternoon to celebrate the victory.
Here are nine photos of Mrs Mortimer on her first day as Hartlepool MP.
1. Boris Johnson back in town
Prime Minister Boris Johnson visited Hartlepool on Friday as well. Photo: Stu Norton
2. A momentous day
After becoming the town's first Conservative MP in a generation, Mrs Mortimer described the result as "historic". She said: "It’s a truly historic result and a momentous day.” Photo: Will Walker / North News & Pictures
3. "Immensely proud"
Mrs Mortimer was declared winner just after 7 am on Friday morning. She said: "I’m also immensely proud to be the first Conservative MP in Hartlepool for 57 years. Not only that I’m the first woman to be elected as MP for this town." Photo: Will Walker / North News & Pictures
4. The Prime Minister's delight
The Prime Minister returned to Hartlepool on Friday following Jill Mortimer's win. During the campaign he visited the town three times. Photo: Stu Norton