CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
The image is a seamless pattern which is derived from a vine .Consequently, the vine got like dots via vectorization.The original vine is here:jp.pinterest.com/pin/500744052301410188/
Source Yamachem
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
From a drawing in 'A Rolling Stone. A tale of wrongs and revenge', John Hartley, 1878.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
White handmade paper pattern with small bumps.
Source Marquis
Prismatic 3D Isometric Tessellation Pattern 6
Source GDJ
Seamless Olive Green Web Background Image
Source V. Hartikainen