Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
An abstract pale yellow paper-like background with stains colored in yellow and green.
Source V. Hartikainen
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Polka Dots Mark II No Background
Source GDJ
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
You know you love wood patterns, so here’s one more.
Source Richard Tabor
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
Utilising a bird from s-light and some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Classic 45-degree pattern, light version.
Source Luke McDonald
Remixed from a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
This is the remix of an OCAL clipart called "Art Nouveau ornament" uploaded by "microcosme".Thanks.This is a seamless pattern of an Art Nouveau ornament.
Source Yamachem
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
A seamless texture of black leather. I think it will look best when used in headers, footers or sidebars.
Source V. Hartikainen
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss