The Mysterious Girl singer said: "I feel great to be here but what I love is that when people are finally allowed to do this, they come in their droves.
"Everybody's here, they're all ready to celebrate.
"The weather's nice, it's not too hot it's not cold - it's the perfect temperature.
"For me to be able to come and do this, it's an honour to be headlining, of course it is. What a great way to come back after such a weird two years."
The free festival also saw performances from tribute acts such as Elite Elton and ABBA Revival, as well local bands including Spinner.
Guitarist Zac Vincent went to St John’s primary and secondary and ended up teaching music there for a couple of years after his music teacher became the head, and appointed Zac.
He said: “I was born in Gravesend, living here all my life, I went to school here.
“I’ve always been doing music, I’ve been in mulitiple bands and a few of the bands have played at the Riverside Festival before.
“I think the first time I played here was when I was eight and I went on stage for a couple of songs with a Queen tribute band.”
Spinner’s new single, Now or Never, is coming out soon.
Also on stage were the GYG Choir from The Grand, Rock Choir and rock covers band Velocer Rapture.
It also featured children’s activities, sports games, craft stalls and food and drink stands.
The festival is usually held every year but had been postponed since 2020 due to the pandemic.
The last time it was held was in 2019, which saw ‘00s group Liberty X stop off in the town for their headline set.