Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Remixed from a PNG that was uploaded to Pixabay by VictorianLady
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
The following orange background pattern resembles a honeycomb.
Source V. Hartikainen
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Prismatic Groovy Concentric Background 2
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Zero CC tileable hard cover cells book texture, 4k, scanned and made by me. CC0
Source Sojan Janso
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
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 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren