"I Just Called to Say I Love You" is a ballad written, produced, and performed by American R&B singer and songwriter Stevie Wonder. It was a major international hit, and remains Wonder's best-selling single to date, having topped a record 19 charts.

The song was the lead single from the 1984 soundtrack album The Woman in Red, along with two other songs by Wonder, and scored number one on the Billboard Hot 100 for three weeks from October 13 to October 27, 1984. It also became his tenth number-one on the R&B chart, and his fourth on the adult contemporary chart; it spent three weeks at the top of both charts, and for the same weeks as on the Hot 100. The song also became Wonder's only solo UK number-one success, staying at the top for six weeks, in the process also becoming Motown Records' biggest-selling single in the UK, a distinction it still held as of 2018. In addition, the song won both a Golden Globe and an Academy Award for Best Original Song. The song also received three nominations at the 27th Grammy Awards for Best Male Pop Vocal Performance, Song of the Year, and Best Pop Instrumental Performance.

The song's lyrics have Wonder surprising his love interest with an unexpected telephone call. Throughout the song, Wonder lists events in a yearly calendar that might prompt someone to call a loved one. Yet he explains no special annual event such as New Year's Day or Halloween spurred the call. He simply wants to tell her he loves her from the bottom of his heart. Cash Box described the song as "a tender and romantic love letter which captures the ever-present and Wonderous feeling of love and optimism."

There was a dispute among Wonder, his former writing partner Lee Garrett, and Lloyd Chiate as to who actually wrote the song. Chiate claimed in a lawsuit that he and Garrett wrote the song years before its 1984 release. However, a jury ultimately sided with Wonder.