A court heard Ms Dewar, 26, needed surgery to her face after the attack.
The attack happened outside Masonic Hall in Macclesfield, Cheshire, last September after boozed-up Campbell had already punched another bridesmaid, Rachel Walsh, 23.
Shocking CCTV played to Chester Crown Court showed the horrific attacks and bride Nicola Campbell in tears.
“My sleep has been affected. I have bad dreams and wake up crying. There has been a ripple effect and I still feel stressed”
On Monday (February 8) sick Campbell was sentenced to one year in jail after he pleaded guilty to one count of assault causing grievous bodily harm on Ms Dewar.
Ms Walsh did not press charges.
Sentencing, Judge Roger Dutton said: “This was your wedding day and at the end of it there was a disagreement in the car park.
“This lady went over to remonstrate with you and without entertaining any conversation with her, you punched her full in the face.
“The consequence was that she was laid flat. It was a punch of some ferocity. It is plain that this has had some impact upon her. She has lost her best friend because her attacker is married to her.”
Jayne Morris, prosecuting, said: “She saw Campbell at the end of the car park, looking angry. He was with another male who was trying to calm him down.
“At this point, Samantha asked Campbell what was going on. He turned to face her and without warning he punched her in the left side of her face.
“As a result of the blow, she fell backwards and the next thing she knew, she was lying on her back on the floor.”
The court heard the bridesmaid was rushed to hospital where surgeons fitted a metal plate to treat a broken cheekbone.