The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
A free background pattern with abstract green tiles.
Source V. Hartikainen
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
A repeating background with a look of paper. I have added some changes to PatCreator. Now you can share your designs by submitting them to a new gallery section. Start by clicking Edit with PatCreator above.
Source V. Hartikainen
Abstract Tiled Background Extended 6
Source GDJ
Heavily remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
This one is amazing, truly original. Go use it!
Source Viahorizon
Prismatic Abstract Geometric Background 4
Source GDJ
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav