Mugabe angrily pulled Zimbabwe out of the Commonwealth bloc in 2003 after its membership was suspended over violent and graft-ridden elections the previous year.
Zimbabwe had fractured relations with the West and became increasingly isolated under Mugabe, who held power since independence from Britain in 1980 until his shock ousting last year.
Foreign affairs secretary Joey Bimha told AFP that Zimbabwe would be represented by Foreign Minister Sibusiso Moyo at the two-day heads of state meeting in London starting on Thursday.
“The minister has been invited by his counterpart in Britain but he will not take part in the deliberations,” Bimha told AFP.
Bimha said Zimbabwe’s attendance reflected President Emmerson Mnangagwa’s intention to improve international relations and boost foreign investment in the post-Mugabe era.
“The president has said he will do everything necessary to re-engage with everyone,” he said.
Zimbabwe left the Commonwealth at the height of land seizures, when white farmers were evicted in favour of landless black people in a policy that wrecked the agriculture sector and triggered national economic collapse.
Mugabe regularly said “to hell with the Commonwealth” — a bloc of former British colonies — and launched bitter verbal assaults against Zimbabwe’s former colonial ruler.
Mnangagwa, Mugabe’s former deputy and a hardline loyalist in the ruling ZANU-PF party, came to power in November after a brief military intervention.