Co-written and first recorded by Paul Williams (1974).
Hit version by Helen Reddy (US #9 1974).
From the wiki: “‘You and Me Against the World’ was the first song written together by Kenny Ascher and Paul Williams and began as a gag song: Williams and Ascher, a member of Williams’s band, had a discussion about their favorite songwriters which led to the spontaneous composition of a song on the subject whose tune, Ascher then realized, had real hit potential. Williams himself debuted ‘You and Me Against the World’ on his 1974 album Here Comes Inspiration, singing it as a traditional love ballad.
“Helen Reddy considered the song’s lyrics too ‘paternalistic’ to be convincing as a woman’s declaration of love for a man; instead, she interpreted the song as a mother singing to a child, which her version clarified by her daughter Traci’s speaking to ‘Mommy’ at the start and end of her recording.”
Helen Reddy, “You and Me Against the World” (1974):