Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
Zero CC asphalt, pavement, texture, photographed and made by me. CC0 WARNING I FOUND A SEAM ON THIS TEXTURE
Source Sojan Janso
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
The following repeating website background is colored in a blue gray color and resembles a concrete wall or something similar to it.
Source V. Hartikainen
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This white background pattern has a seamless grunge style texture. Here's a white grunge style background pattern. Use it as a tiled background image on web sites or for other purposes.
Source V. Hartikainen
Might not be super subtle, but quite original in its form.
Source Alex Smith
Element of beach pattern with background.
Source Rones
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
A background tile of dark textile. Made this a long time ago and just now decided to publish it.
Source V. Hartikainen
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Sort of reminds me of those old house wallpapers.
Source Tish
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin