Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
From a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Clover with background for St. Patrick's Day. Add to a card with a doily, ribbon, a leprechaun or other embellishments.
Source BAJ
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
Embossed lines and squares with subtle highlights.
Source Alex Parker
From a drawing in 'La Principauté de Liège et les Pays-Bas au XVIe siècle', Société des Bibliophiles Liégeois ,1887.
Source Firkin
ZeroCC tileabel stone granite texture, edited from pixabay. CC0
Source Sojan Janso
The name tells you it has curves. Oh yes, it does!
Source Peter Chon
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ