"Mom, I love you so much," she said through tears. "Thank you for teaching me that God has always been leaning in my direction."
King won the Oscar for best supporting actress for her role in "If Beale Street Could Talk." It's the first Oscar and first nomination for King, who has won three Emmy Awards for her work on television.
King also thanked author James Baldwin, whose novel is the basis for the film from director Barry Jenkins.
Regina King walks the Oscars Red Carpet
"To be standing here representing one of the greatest artists of all time - James Baldwin. James Baldwin bursts this baby and Barry nurtured her, surrounding her with so much love and support. So it's appropriate to be standing here because I am an example of what it looks like when support and love is poured into someone," King said."God is good, all the time."
The best supporting actress award was presented by Maya Rudolph, Tina Fey and Amy Poehler after they delivered the night's opening monologue.
Earlier in the evening, King brought Old Hollywood alive on the red carpet in a romantic white gown with a touch of sparkle and a long train. She paired her strapless ruched Oscar de la Renta gown with a white gold and diamond bracelet and pear-shaped diamond drop earrings from Chopard.
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As she hurried down the red carpet with a companion holding her train, King received a rousing round of applause from the audience members watching from the bleachers erected outside the Dolby Theatre.
PHOTOS: Oscars 2019 carpet fashion; stars arrive at 91st Academy Awards
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Lady Gaga attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Regina King attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Glenn Close attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Melissa McCarthy attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Yalitza Aparicio attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Lucy Boynton and Rami Malek attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Helen Mirren attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Bradley Cooper and Irina Shayk attend the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Rachel Weisz attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Emma Stone attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Charlize Theron attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Jason Momoa and Lisa Bonet attend the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Keegan-Michael Key(L) and Elisa Pugliese attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Amatus Sami-Karim and Mahershala Ali (R) attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Donna Jordan and Michael B. Jordan attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Sarah Paulson attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Jennifer Lopez and Alex Rodriguez attend the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Viggo Mortensen attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Laura Dern attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Allison Janney attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Christian Bale and Sibi Blazic attend the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Queen Latifah attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Amy Adams attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Cicely Tyson attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Tessa Thompson attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Molly Sims attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Brie Larson attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Maya Rudolph attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Joanne Tucker and Adam Driver attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Amy Poehler attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Octavia Spencer attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Tina Fey attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Jordan Peele and Chelsea Peretti attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Jennifer Hudson attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Mike Myers and Kelly Tisdale attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Sam Rockwell attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Leslie Bibb attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Angela Bassett attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Kacey Musgraves attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
David Oyelowo attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Gemma Chan attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Hannah Beachler attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
U.S. Representative John Lewis attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Nicholas Hoult and Joe Alwyn attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
James McAvoy attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Best Live Action Short Film nominee for 'Mother' director Rodrigo Sorogoyen (R) and Marta Nieto attend the 91st Annual Academy Awards on February 24, 2019 in Hollywood, Calif.none
Sandy Powell attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Gabriela Rodriguez attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Linda Cardellini attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Trevor Noah attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Tonya Lewis Lee and Spike Lee attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Spike Lee, fashion detail, attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Lynette Howell Taylor attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Billy Porter arrives at the Oscars on Sunday, Feb. 24, 2019, at the Dolby Theatre in Los Angeles.none
Tom Morello attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Marshall Curry attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Awkwafina attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Mark Ronson attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Giada Colagrande and Willem Dafoe attend the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Barry Jenkins (R) attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Michelle Yeoh attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Marina de Tavira attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Adam Lambert attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Gwilym Lee, Allen Leech, Joseph Mazzello, and Ben Hardy attend the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Fatma Al Remaihi attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Questlove attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Stephan James and Shamier Anderson attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Laura Harrier attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Emilia Clarke attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Diane Warren attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Elaine Welteroth attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Serena McKinney and Ludwig Goransson attend the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Cinematographer Robbie Ryan (L) attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Marie Kondo attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Louise Bagnall and Nuria González Blanco attend the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Deborah Davis attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Danny Glover attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Producers Maria Gracia Turgeon and Evren Boisjoli attend the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Nancy García García attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Best Production Design nominee Fiona Crombie and Peter Knowles attend the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Ashley Graham attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Yuichiro Saito attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Meagan Good attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Constance Wu attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Danielle Macdonald attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Elsie Fisher attends the 91st Annual Academy Awards at Hollywood and Highland on February 24, 2019 in Hollywood, California.none
Jenifer Lewis of ''black-ish'' and Shangela from ''A Star Is Born'' arrive at the Oscars on Sunday, Feb. 24, 2019, at the Dolby Theatre in Los Angeles.none
Laura Marano arrives at the Oscars on Sunday, Feb. 24, 2019, at the Dolby Theatre in Los Angeles.none
Wolfgang Puck, third from left, arrives with his team and Oscar inspired fare, at the Oscars on Sunday, Feb. 24, 2019, at the Dolby Theatre in Los Angeles.none
Kristin Cavallari arrives at the Oscars on Sunday, Feb. 24, 2019, at the Dolby Theatre in Los Angeles.none
Shangela arrives at the Oscars on Sunday, Feb. 24, 2019, at the Dolby Theatre in Los Angeles.none
The Associated Press contributed to this report.