The 22-year-old went into the games with a world-leading time for this year, and fulfilled that promise by winning Britain’s first athletics Olympic gold in eight years.
Hodgkinson appeared poised and in control from the outset, effortlessly maintaining her lead down the final straight.
During a lap of honour, she grabbed a union flag, hugged World Athletics president Sebastian Coe, and high-fived admirers.
Speaking at the track, she remarked, “I’m very thrilled… I am now the Olympic champion for the next four years, and nobody can take it away from me.”
Hodgkinson, from Atherton in Wigan, had been focussed on gold after finishing second in Tokyo three years ago.
Her 800m victory came 20 years after fellow British runner Kelly Holmes won gold at the same distance in Athens.
It is also the first athletics Olympic gold for a British woman since Jessica Ennis-Hill won the heptathlon in London 2012.
On Monday evening, Team GB added to their medal tally by breaking the world record three times in the women’s cycling sprint in the velodrome.