Lucas Smout the Younger or Lucas Smaut was a Flemish painter of coastal and country scenes who was active in Antwerp.

Details about the life of Lucas Smout are scarce. He was born in Antwerp as the youngest child of the painter and art dealer Lucas Smout the Elder and Anna Maria Tijssens. His father had studied under Artus Wolffort and was a figure painter. His brother Dominicus (or Domien) became a genre painter while two of his sisters married painters. His mother was a member of the prominent Tijssens or Tyssens family of artists in Antwerp, which included artists such as Jan Baptist Tijssens the Younger. His father died in 1674 and his mother in 1686. His sister Clara Catharina continued to operate the art and painting materials business of her parents. Upon discovering Lucas' artistic talent, she sent him to study art under a master.

Lucas was registered in 1685–86 in the registers of the Antwerp Guild of Saint Luke as a pupil of the marine artist Hendrik van Minderhout.

Smout was active in Antwerp throughout his career but must have visited the Dutch Republic since he painted a few views of Scheveningen beach. Smout was not very productive as he suffered from gout, which affected his hands. This may also be the reason why he remained unmarried and lived in the house of his eldest sister Clara Catharina who was married to the painter Gonzales Franciscus Casteels. Another sister married the painter Jacob Herreyns the Elder.

He died in Antwerp in 1713.