Rihanna's father, Ronald Fenty, was laid to rest in Barbados on Tuesday after dying in May ... and Riri and A$AP Rocky were amongst the mourners paying their respects.

A glowing-and-pregnant Rihanna was photographed carrying their son, Riot, as Rocky trailed not too far behind as he hoisted up RZA as they entered the Garfield Sobers Gymnasium, where the celebration of life was held.

It was a march of the R's ... Rihanna, Rocky, RZA, Riot -- even Ronald's fiancée, Rosemary, was spotted in the crowd.

Ronald is survived by his six children, 10 grandchildren and a few great-grandkids ... Rihanna was dubbed "The Right Excellent" within the obituary pages.

We broke the story ... Ronald died at 71 from a combination of respiratory failure, cancer and pneumonia ... with kidney damage also playing a significant factor.

A tragic day but the circle of life will come 'round soon when Rihanna gives birth to her and Rocky's 3rd child later this year.