Honestly keeping a toddle quiet is mission impossible, i just had a backyard wedding and we got a super nice photo from laughing at our eldest doing the funniest deep giggle when it was dead quiet,because she was so excited we were getting married!
As long as its not tantrums, theyre a toddler, you cant expect them not to make noise!???? my other alternative would be ga babysitter, but the suggestions of books and colouring books are also an awesome idea! Personally i would make it a one off day with an ipad/my phone for the ceremony ????

My daughter would always look at her books or play with her favourite toys.

I would bring a bag with special toys / things to keep him occupied

You probably can’t, but picture books (ceremony) and coloring books (reception) go a very long way.

Don’t even try! It will add some lighter moments to the ceremony and give guests something to giggle about

I really don’t think people will expect a toddler to be silent during a ceremony. If it’s that important, don’t take them to the ceremony, just the reception. Might be easiest

All I can say is good luck in trying!

My three year old found my friends wedding so boring he fell asleep in my arms so did the little flower girl who feel asleep behind the brides dress… Dont stress…Although he was toilet training at the time and decided to yell out in the middle of the ceremony that he needed to wee.. I reminded him he had a nappy on to feel free to wee in in it.. I told the bridal couple afterwards and they laughed just incase it was picked up by the video…

Will there be other young children there? Will there be an area where they can play without disturbing all the guests and the parents take turns of watching them? One way to heopefully keep them occupied and hopefully quiet is to take a few small toys they can play with at the table or on the floor but not where they will inconvenience others including staff who are serving meals, drinks etc.
Another thing you can take if they are interested is colouring in books or sheets of paper and coloured pencils and let them draw, colour in etc. I know some people who regularly do this if they go to a hotel for dinner. The kids are only given them after their plates have been cleared away. The parents/ grandparents/ other relatives have only ever received compliments about the good behaviour of the children, never bad. They were trained while they were still in a highchair. Sitting on chairs they still don’t leave the table and run around at all; even though a lot of other kids “run riot” get in the way of waiting staff carry hot meals etc.