I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Black brick wall pattern. Brick your site up!
Source Alex Parker
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
From a drawing in 'Jardyne's Wife', Charles Wills, 1891.
Source Firkin
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett