I've been fighting this invasive weed in my lawn for several years. I've tried different weed killers but it continues to spread. People at garden centers say they've never seen it before. I hope someone can identify it and tell me how to get rid of it.

Maybe dodder?
https://bygl.osu.edu/node/1074

I've never seen white examples...
And can't tell if the strings are coming from the ground or are an actual part of the plants...

Maybe closer close-ups?

A few closer photos. This weed has the county extension office baffled. But with all the bagged soil, mulch and compost being sold these days, it's hard to say where any new weed might be coming from.

Hmmm... So the threads are actually growing out of the grass blades?

I found white threads here:
https://www.back2frontturf.com...

But not really a good match.

I found red thread fungus disease, but not white... Although... some of the pics google shows me do seem kinda whitish...

https://www.canr.msu.edu/news/...

https://gcmonline.com/course/e...

So...
What type of turf are you intending to grow here?

I'm not sure what kind of grass it is, but your mower blade(s) needs to be sharpened.

Stone, thanks so much for those links! Seems my weed could be a couple of those. I might go back to the extension office and see if a different person might know for sure.

CalPoly, I noticed that. too. LOL I recently hit a metal garden stake that was down among some weeds. I'm going to buy a new blade and have this one sharpened so I always have one ready. Thanks!

It reminds me of this but I don't know that Pennisetum would be hardy in Ohio (pics 4 and 5 are most similar):

https://turf.purdue.edu/founta...

I'm pretty sure it isn't red thread disease as I'm very familiar with it and never seen it look like that.

Many thanks, Sue! Some of those photos look exactly like what I have. I have some fountain (zebra) grass nearby and that might be the culprit. I plan to dig up and get rid of the fountain grass this fall and I'll try digging out the individual clumps of this weed in the lawn and sow grass seeds. Nothing to lose at this point. Thanks again, I'm grateful for the response!

Pennisetum alopecuroides! I've never seen it cut with a mower.
Another option is Tumble Windmillgrass, Chloris verticillata.