Jenner's donation will be used to buy hundreds of thousands of face masks, face shields and other protective gear to be used by healthcare professionals working the frontlines.

Dr. Thais Aliabadi -- who delivered Stormi -- thanked Jenner for the generous gift Wednesday, saying, "I am speechless, my eyes are filled with tears of joy and my heart is overwhelmed with gratitude. I made a wish to the Universe to gather protective masks for our brave healthcare workers and today my dream came true."

She continues, "I have never felt more blessed to be a doctor, as helping our brave ER and ICU workers feels just as gratifying as helping my own patients. From the bottom of our hearts, THANK YOU Kylie Jenner. You are my hero. This generous donation will help save many precious lives. Our world is a better place with you in it. I love you so much."

Kylie joins a growing list of celebs to make serious donations to the efforts ... Arnold Schwarzenegger also donated $1 million and companies like Apple and Yelp have pledged masks and money to the fight.

Kylie was also one of the first celebs to use their platform to urge fans to stay inside and quarantine. The Surgeon General made a plea to Kylie, Kevin Durant and others on TV as a way to reach a younger audience ... Kylie's got 167 million followers just on Instagram.