Jennifer Garner has announced the death of her father, William John Garner, at the age of 85.

The 13 Going On 30 and Elektra star, 51, said her father “passed peacefully” on Saturday afternoon (30 March), and that he was leaving behind a “loving legacy”.

“We were with him, singing ‘Amazing Grace’ as he left us (did we carry him across or scare him away – valid question),” she joked in a post on Instagram, alongside a series of pictures of the pair together.

“While there is no tragedy in the death of an 85-year-old man who lived a healthy, wonderful life, I know grief is unavoidable, waiting around unexpected corners.

“Today is for gratitude.

“We are grateful for Dad’s gentle demeanour and quiet strength. For how he teased with a mischievous smile, and for the way he invented the role of all in, ever patient girl dad. We are grateful for his work ethic, leadership and faith.”

Jennifer Garner (right) with her parents William and Patricia at the premiere of ‘Elektra’ in 2004 (Getty Images for Twentieth Century Fox)

Garner said her family were extending their gratitude to the Charleston Area Medical Centre and City of Hope – which is a “world-renowned pioneer in cancer research, treatment and prevention”.

“Your care extended Dad’s life and gave him time to be in his favourite spots – surrounded by daughters and grandchildren, cheering for his beloved Aggies, captaining a boat, and – most of all – next to his wife of 59 years, our Mum,” she said.

“There is so much to say about my dad – my sisters and I will never be done talking about how wonderful he was, so bear with us – but for today I share these memories with my appreciation for the kind and brilliant man, father, and grandfather he was, as well as the loving legacy he left behind.”

Last year, Garner wrote about her father on Instagram after she gifted him a heartwarming trip down memory lane as a birthday surprise.

The actor visited her hometown of Charleston, West Virginia and used part of her time to plan an early birthday present for her father.

“Dad’s early birthday surprise: a ride in his childhood car – [a] 1948 Studebaker Champion,” she wrote on social media.

Her father’s birthday fell on 21 September, which is famously referenced in the Earth, Wind & Fire song “September.” Jennifer referenced the date in an older birthday tribute post from 2017.

“My dad’s birthday = the 21st night of September = #earthwindandfireday,” she wrote, quoting the lyric of the song, which also played in the background of the clip. “We always knew you were the coolest, Dad! Happy Birthday!”