Hudson-Smith successfully retained the title he first claimed four years ago in Berlin - having taken silver in Zurich four years earlier - at Munich 2022, adding to the silver recently won at the Commonwealth Games in Birmingham and World Championship bronze achieved in Oregon earlier this summer.
Alex Haydock-Wilson made it two Britons on the podium after battling for bronze, with Switzerland’s Ricky Petrucciani claiming silver.
Hudson-Smith, who is targeting further success in the 4x400m relay, said: "It was a good victory and I did exactly what I wanted to do. I'm so happy to be European champion again.
"I wanted to wind it up and try and be calculated, try to go for the gold. I think people thought I'd go out absolutely blazing on the back straight, so I used them and I controlled it and wound it up.
"It has been a busy summer, but I am so pleased to be able to compete against the best in the world. There's not much you can ask for really."
Bronze medallist Haydock-Wilson, who blamed himself for the GB quartet's failure to make the final of the mixed 4x400m relay in Eugene, admitted that experience had taught him an invaluable lesson after crossing the line in 45.17 seconds.
He said: "Honestly, now that enough time has passed, I couldn't be grateful enough for that experience. It was by far one of the worst in my life, I wouldn't wish it on anyone.
"It taught me so much, it made me fearless as it took me a to a point where things really couldn't get any worse, and I realised, 'This is terrible, but it's not the worst thing in life, so why should I get anxious on race day when I know I am capable of so much good stuff?'.
"This means so much, just what this represents - it's more than a piece of metal, is a culmination of so much hard work, so much pain, so much joy as well."
There was no such joy for Britain's Victoria Ohuruogu in the women's 400m as she finished fourth behind the Netherlands' Femke Bol - favourite also to claim gold in the 400m hurdles - in 50.51, two hundredths ahead of Ireland's Rhasidat Adeleke, who set a new national record.
Ohuruogu said: "I really wanted a medal, but if you take everything into consideration, I have nearly run my PB again today so I'm happy."
Andrew Pozzi made it to the final of the 110m hurdles as a fastest loser, but finished sixth in 13.66 seconds as Spain's Asier Martinez edged out France's Pascal Martinot-Lagarde for gold.
Jade O'Dowda set a new personal best in the high jump, but ended the first day of the heptathlon in 11th place.
O'Dowda, who took Commonwealth bronze two weeks ago, cleared 1.80m after clocking 13.72 seconds in the 100m hurdles, and later posted 12.98m in the shot put and ran 24.80 in the 200m on a day when reigning champion Nafi Thiam established a 214-point lead over the rest of the field.
Jacob Paul also had a personal best in the 400m hurdles as he advanced to the semi-finals in 49.40 seconds, finishing second in his heat.
Commonwealth bronze medallist Naomi Metzger took only one jump in qualifying for the women's triple jump, deciding the 14.24m - her second best result of the season - would do as she reached the final with the fourth best result.
Double Commonwealth champion Nick Miller cruised into the men's hammer final with a throw of 76.09m, while Lawrence Okoye qualified in the men's discus with a throw of 62.56m.
Additional reporting by the Press Association.