A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This seamless web background texture looks like gray stone. It's great for using as a background image on web pages, or on some of their elements. Anyway, I hope you will find use for it.
Source V. Hartikainen
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Light honeycomb pattern made up of the classic hexagon shape.
Source Federica Pelzel
Abstract Tiled Background Extended 12
Source GDJ
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
Prismatic Groovy Concentric Background No Black
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
A repeating background with wood/straw like texture.
Source V. Hartikainen