Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
From an image on opengameart.org shared by rubberduck.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A bit of scratched up grayness. Always good.
Source Dmitry
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Adapted from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Classic vertical lines, in all its subtlety.
Source Cody L
A seamless pattern with green and yellow diagonal lines on top of a white dotted background.
Source V. Hartikainen
Here's an yet another background for websites, with a seamless texture of wood planks this time.
Source V. Hartikainen
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
A seamless pattern formed from a square tile based on a jpg on Pixabay. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
A simple bump filter made upon request at irc #inkscape at freenode. Made a screen capture of the making here: https://youtu.be/TGAWYKVLxQw
Source Lazur URH
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler