"You Still Believe in Me" is a song by American rock band the Beach Boys from their 1966 album Pet Sounds. Initially conceived as "In My Childhood", it was the first songwriting collaboration between Brian Wilson, the group's de facto leader, and songwriter Tony Asher. Wilson sang the lead vocal.

The lyrics are about a man who, while acknowledging his irresponsible behavior and unfaithfulness, is impressed by the unwavering loyalty of his lover, who is left shouldering the stability of their relationship. Wilson's then-wife Marilyn surmised that this choice of subject matter was indebted to the couple's marital struggles at the time.

One of the first songs produced for Pet Sounds, Wilson recorded the track between January and March 1966 with the aid of his bandmates, Asher, and 13 session musicians who variously played harpsichord, clarinets, 12-string electric guitars, timpani, finger cymbals, pianos, basses, and bicycle horn. Wilson and Asher created the song's ethereal intro by plucking a piano's strings with a bobby pin.

"You Still Believe in Me" was originally conceived by Wilson as a song titled "In My Childhood". According to biographer Peter Ames Carlin, "Brian already had a set of lyrics that fit with the tune's sweet vaguely melancholy sound and quirky textural effects (a bicycle horn and bell). But he didn't like his lyrics anymore and wanted to adapt the tune to another concept." In December 1965, Wilson contacted jingle writer Tony Asher about a possible lyric collaboration, wanting to do something "completely different" with someone he had never written with before. Asher accepted the offer, and within ten days, they were writing together. Wilson played some of the music he had recently recorded and gave a cassette to Asher containing the backing track to "In My Childhood".

There are discrepancies from Asher as to whether "In My Childhood" had a recorded vocal or a different melody at this juncture. Quoted in the 1978 biography The Beach Boys and the California Myth, Asher said, "We wiped off those vocals and that melody and rewrote it. ... The [chord] changes were the only thing that stayed the same." However, in a 1996 interview, Asher said, "Brian never let me hear the lyric to it. I didn't hear the vocals, but I could hear a little bit of some backgrounds and stuff that were leaking through other [microphones] but I didn't really hear any melody to it." Later, Asher revised his story again, "If I remember correctly, the original melody sounded exactly the way it does on the album, and someone had already written lyrics."

The result of Asher's tryout was "You Still Believe in Me", and the success of the piece convinced Wilson that Asher was the wordsmith he had been looking for. In a 1996 interview, Wilson summarized "You Still Believe in Me" as a "little 'Boys Choir'-type song with me doing the soprano. Very, very spiritual."

I always thought [Brian] wrote that with me in mind. He knew that he was not a good husband, and that I was very lonely, and really didn't get much back from him, and he made me cry all the time, because it was hard to understand that kind of life, what was going on for him. It was like there wasn't much of a relationship [between us].

Biographer Mark Dillon described the lyrics of "You Still Believe in Me" as "a musing about the ups and downs of adult romance". In the song, the narrator expresses appreciation for his lover's unwavering loyalty while confessing to his irresponsible behavior and unfaithfulness. He admits that he is "not where I should be", and though he puts forth effort in the relationship, he has occasionally "fail[ed] myself". The relationship's stability is thus shouldered by the more mature partner.