0658 GMT July 31, 2021
Krejcikova beat Russia's Anastasia Pavlyuchenkova 6-1 2-6 6-4 in only her fifth major singles draw appearance, BBC Sport reported.
The former doubles world number one paid tribute to mentor Jana Novotna, who died in 2017 at the age of 49, saying she owed her success to her.
"She is looking after me from up there," said 25-year-old Krejcikova.
Krejcikova has often spoken about the impact of former Wimbledon champion Novotna, who died from ovarian cancer.
When she was 18 and an aspiring player, Krejcikova's parents took her to Novotna's house and asked the former world number two for some advice.
Novotna saw something special and became her coach, mentor and friend until she died.
"I was going through a really hard time when Jana passed away, I was with her most of the time. Her last words were pretty much 'just enjoy it and try to win a Grand Slam'," Krejcikova said.
Pointing to the sky, she added: "I know from somewhere she is looking after me and all that happened in the last two weeks is pretty much because she is looking after me.
"It is amazing I had the chance to meet her and she was an inspiration. I hope she is really happy and I am extremely happy."
"I'm super happy I was able to enjoy it. I'm just really happy," said world number 33 Krejcikova, who has also won two Grand Slams women's doubles titles and three mixed doubles titles.
"It is hard to put into words because I cannot believe what just happened. I cannot believe I actually won a Grand Slam."
Leading up to the final, Krejcikova was keen to avoid being labelled a 'doubles specialist' and victory against 31st seed Pavlyuchenkova ensured that will never be the case.
Krejcikova – who counts sewing and doing the gardening with her parents among her hobbies – understands there will be more focus on her now, but says the triumph will not change her outlook on her life and career.
"I'm planning to work hard again. This is such a big motivation to just work hard, enjoy this journey, enjoy tennis and everything," said Krejcikova.
"I guess a lot of things are going to change. For me, I'm just going to still be the little girl from my little city [Ivancice, near Brno], that used to start on the tennis wall. Nothing's going to change."