Luis Guilherme Lira dos Santos (born 9 February 2006) is a Brazilian footballer who plays as a winger for Premier League club West Ham United.

[5] Luis Guilherme made his first team debut on 12 April 2023, coming on as a second-half substitute for José Manuel López in a 4–2 home win over Tombense, for the year's Copa do Brasil.

[9] He made his West Ham debut on 5 October coming on as an 85th minute substitute for Mohammed Kudus in a 4–1 Premier League win against Ipswich Town.

[14] Luis Guilherme played in five matches, totaling 191 minutes, contributing to Brazil's first U20 South American Championship title in 12 years and securing a spot in the FIFA U-20 World Cup after an eight-year absence.

[15][16] A technical winger with good on-field decision making, Luis Guilherme is renowned for his pace, clocking a top speed of 36.4km/h in the 2022 Copa do Brasil Sub-17 final against Vasco da Gama.