Quick & Easy! The Star and Octagon Quilt Block: A Step-by-Step Tutorial for a 10″ Finished Block

The Star and Octagon quilt block is a fun and surprisingly easy 10″ pieced block that creates big impact with simple shapes. Made with half square triangles, squares, and snowballed rectangles, this design comes together quickly using just two contrasting colors plus a background fabric.

On its own, the block has a bold geometric look – but when you sew multiple blocks together, beautiful stars emerge across the quilt top as a striking secondary design. It’s a perfect choice for confident beginners and seasoned quilters alike who love classic patchwork with a dynamic twist.

Update: I now have a pattern for this block available for purchase in my Etsy shop. Check it out by clicking this link: STAR AND OCTAGON

Fabric Requirements for a 10″ Finished Star and Octagon Quilt Block:

Light/Cream: 4 – 2.5″ x 6.5″ rectangles, 4 – 3″ squares, and 1 – 2.5″ square
Dark/Green: 2 – 3″ squares, and 8 – 2.5″ squares
Dark/Purple: 2 – 3″ squares, and 4 – 2.5″ squares

Sewing Directions:

Half Square Triangle Units:

Step 1:

Using the Light/Cream 3″ squares and the Dark/Purple 3″ squares, make Half Square Triangle (HST) units as shown. You can find my tutorial for making HST units at https://quiltembroiderypdf.com/how-to-sew-a-basic-half-square-triangle-block. Here are the steps corresponding to the images in the picture below.

Match up a Light/Cream square and a Dark/Purple square right sides together. Mark a diagonal line from corner to corner on the back of the Light/Cream square and sew 1/4″ (or a little less) on each side of the line. (top left image)
Cut along the diagonal line. You will have 2 half-square triangle patches. (top right image)
Open up the patch and press the seam allowance toward the Dark/Purple fabric. (bottom left image)
Square up/trim the units to 2.5″ square. (bottom right image)

Step 2:

Repeat Step 1 for a total of four Cream/Purple HST units as shown below.

Step 3:

Repeat Steps 1 and 2 only substituting the Dark/Green 3″ squares for the Dark/Purple squares.

Snowballed Rectangle Units:

Step 4:

Make four Snowballed Rectangle units using the Light/Cream 2.5″ x 6.5″ rectangles, and the Dark/Green 2.5″ squares. This unit goes together just like half of a Snowball block except that you use a rectangle for the base. You can find my tutorial for making a Snowball block at https://quiltembroiderypdf.com/how-to-sew-a-basic-snowball-block

Here are the first steps, going from top to bottom:
Mark a diagonal line from corner to corner on the back of a 2.5″ square and sew the 2.5″ square to one corner of the Light/Cream rectangle along the marked line. Note the orientation of the marked line.
Match the corners of the 2.5″ square and press.
Open up the 2.5″ square and trim the seam allowance.
Refold.

Step 5:

Repeat Step 4 for a total of four partial units like the ones in the picture below.

Step 6:

Repeat Steps 4 and 5 on the other end of the Light/Cream rectangles as shown below.

Center Unit:

Step 7:

Lay out the Step 2 HSTs, the four Dark/Purple 2.5″ squares, and the Light/Cream 2.5″ square in a typical Nine Patch configuration as shown below.

Step 8:

Sew the units into three rows.

Step 9:

Press the seam allowances toward the Dark/Purple squares as shown in the picture below.

Step 10:

Sew the three rows together – this makes a cute block all on its own!

Step 11:

Press the seam allowances toward the center of the unit as shown below.

Putting It All Together:

Step 12:

Lay out the Center unit, the Snowballed Rectangle units, and the Step 3 HST units as shown.

Step 13:

Once again, sew the units into three rows.

Step 14:

Press the seam allowances toward the Snowballed Rectangle units as shown in the photo below.

Step 15:

Sew the three rows together to complete the the block.

Step 16:

All that’s left is to press the seam allowances away from the center of the block as shown.

Layout Ideas:

Here is your basic 4 x 4 layout using colors similar to the tutorial.

This is the same layout as above but with narrow (1″) sashing and cornerstones added.

This is an alternating layout using a chain block in coordinating colors for the alternate block.

This is another alternating layout where every other block is a Snowball block. I also added in the light green (instead of blue) on the corner HSTs. Put some fancy quilting or applique or embroidery in all that open space!

This is an on-point layout with the light fabric also being used for the setting triangles.

Here’s another on-point layout – this time alternating with a simple chain block that extends into the setting triangles. I also changed the coloring of the corner HST units.