A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
This is the remix of "Strawberry Pattern Background" uploaded by "GDJ". Thanks. I realigned strawberries so as to get seamless and changed the BG color.
Source Yamachem
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Prismatic Geometric Pattern Background No Black
Source GDJ
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.
Source Firkin
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
A white version of the very popular linen pattern.
Source Ant Ekşiler
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
Background pattern originally a PNG drawn in Paint.net
Source Firkin
If you don’t like cream and pixels, you’re in the wrong place.
Source Mizanur Rahman
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
Seamless Prismatic Geometric Pattern With Background
Source GDJ