The boy-band singer, 25, who previously dated Cheryl Tweedy, 10 years his senior, is believed to have been seeing Campbell for the past two months.
A source said he “is head over heels” for the model, who is 23 years older than him, and “can’t believe his luck”. Rumours about a relationship between the pair started after they were spotted out together several times, and swopped flirtatious public messages on Instagram. It is thought they are about to go public.
The source said: “Liam has been seeing Naomi for a while. He’s mad keen on her. They are definitely an item and have been seeing a lot of each other.
“Liam thinks she’s amazing and beautiful, and has said their intimate time together has been mind-blowing. He seems really into her and acting like he can’t believe his luck. He obviously likes a beautiful older woman.”