João Guilherme de Ávila Costa (born February 1, 2002) is a Brazilian actor and singer. He became nationally known for playing the character Joaquim, one of the main characters in the remake of the children's soap opera Cúmplices de um Resgate.

He began his acting career in 2009, at the age of 7, playing Vinícius in the short film Vento, alongside Vivianne Pasmanter. In 2012, he starred in the film Meu Pé de Laranja Lima, playing Zezé. An adaptation of the classic of the same name by José Mauro de Vasconcelos. João Guilherme began his musical career while playing Joaquim in Cúmplices de um Resgate.