Catherine O'Hara's Private Funeral Was Held on Valentine's Day

Catherine O'Hara's family and friends laid her to rest on Valentine's Day ... coming together to say their farewells two weeks after her sudden death.

Her funeral service was held at St. Martin of Tours Catholic Church in Los Angeles ... according to a booklet from the service posted on social media by actress Kelly Lynch.

Catherine's funeral service booklet featured an old photo of her, seemingly from her high school days ... and Kelly captioned the post, "Rest in peace darling Catherine 💔."

Kelly also shared a throwback photo of Catherine posing on the hood of a classic car.

We broke the story ... Catherine died on January 30 after being rushed to the hospital in serious condition following a medical emergency at her home.

As we first told you, Catherine's death certificate lists the immediate cause of death as pulmonary embolism, with rectal cancer as the underlying cause.

Catherine was cremated and her remains were given to her husband, Robert "Bo" Welch ... and now she's had her funeral service.

Catherine was 71.