LOS ANGELES: The world's oldest person celebrated her 115th birthday on Monday with music, cake and a letter of congratulation from US President Barack Obama.

Gertrude Baines, who became the planet's longest living human in January following the death of Portuguese woman, Maria de Jesus, also 115, marked her birthday at Los Angeles Western Convalescent Hospital.

Baines - who attributes her longevity to her religion and clean living - attracted worldwide headlines last November when she became the oldest African-American to vote for Obama during the presidential election.