Large cushions for living room.

you could get someone to make some for you

80 x 80 is the standard size for pillows in Germany. No one knows why.

Why do you want cushions and why in that size? I'm honestly intrigued. I have a few on my settees (40 x 40) but my sons all throw the cushions onto another seat when they sit down and the grandchildren only use them for cushion fights. So I sometimes think I shouldn't bother.

Amazon have plenty of that size, plenty designs and colours.

What colours/designs are you looking for jaxjacky?

Thank you Mini floor cushions, good plan.
Whiff very thoughtful, but sewing machines and I parted company at senior school, on not very good terms!
Springy worth knowing, thanks.

IKEA and Wayfair have that size, I purchased some recently.

If you are a knitter you could knit some Aran panels.
I’ve crafted some Bargello covers, patchwork etc. With making your own covers the choice is endless.

Jaxjacky if you have a sewing machine. It would be easier and probably cheaper to make your own cushions. Also you there is a wide choice of fabrics. All you would need is to large squares plus seam allowance for the cover. If you are good at sewing you could put a zip in . I am can't put zips in . What I do is sew round 3 sides and the end I want to open sew so far in each end and leave a gap to be able to put the cushion in. You can either sew on some velcro, put pops on or even make ties and sew on each side and tie or some other fastening .The cushion inner buy white poly cotton and loose toy stuffing that is washable. Sew the inner the same as outer the fill with stuffing and either hand sew or machine sew the gap. Then put into cover.

I am not an expert sewer but it's only straight lines. That's what I did but I made rectangle's.

Others may have better ideas.

Your choice will be limited because of the large size. You say you have never bought cushions before so, if you resort to buying the covers and pads separately, buy covers an inch or two SMALLER than the pads.

For cushions of that size, I would look for floor cushions. My DD bought some for use on her sofa bed. I'm sorry I don't know where she bought them, possibly IKEA.
Have a look at these.

Meant 80x80cms.