The world champion finished 0.30s behind Ukraine’s Andriy Govorov at the Tollcross International Swimming Centre while going close to a new personal best.
It was part of a memorable night in the pool at Glasgow 2018 for Great Britain, with Duncan Scott and the 4x200m freestyle relay women picking up golds.
Now Proud is already looking ahead to the men’s 50m freestyle today, with one medal safely in his back pocket.
“A silver medal is great considering who I was up against,” the 23-year-old said.
“Coming into this meet I kind of knew that a silver medal was a realistic target.
“But you’re always fighting for that extra spot so I’m happy with how it went and I’m happy to be so close to a personal best.
“Back under 23 seconds again and it’s a good snapshot for the season.
“Hopefully come next week I can start chipping away at the times again.”
Elsewhere, James WIlby could not reach a third straight final as he fell at the first hurdle in the men’s 50m breaststroke.
The York swimmer, who took silver in the 100m and 200m earlier this week, was the third fastest Briton behind Adam Peaty and Ross Murdoch – and only two are allowed to progress.
“The 50m is a fun event for me and I am happy with the week as a whole,” he said.
Home city hero Scott defied a difficult lane draw to claim his improbable 200m freestyle gold medal while Freya Anderson led Great Britain’s women’s 4x200m freestyle relay team to gold.