Tableau Box Plot is useful for graphically visualizing the numeric data, group by specific data. Let us see how to Create a boxplot in Tableau with an example.
How to Create a Tableau Box Plot
In this example, we are going to create a boxplot in Tableau. For this, first drag and drop the Sales Amount from Measures Region to Rows Shelf, and Color from Dimensions region to Details field present in Marks Shelf.
The Tableau intelligence automatically creates the Bar Chart, but we want to create a Box plot. So, please select the below shown option from the Show Me window.

From the below screenshot, you can see the Tableau Box plot.

Let me drag the English Country Region Name from Dimensions to Columns Shelf. It will create for each country

You can hover over the mouse on them to see the Median, Upper Quartile, Lower Quartile, and the Whisker values.

Change Colors of a Tableau Box plot
We show you how to change the colors of the rectangles. We have two different approaches to create this.
First Approach: Please right-click on the rectangle and select the Edit.. option from the context menu.

Once you select the Edit.. option, a new window called Edit Reference Line, or Band will open to style it.

Second Approach: Go to the Format menu and select the References Lines… will open the Format Reference Lines tab.

Let me change the Fill color to the Red pallet.

Next, we are changing the Border width and border color.

Lastly, we are changing the Whiskers width and color

Change Colors of a dots in Tableau Box Plot
This example explains how to add colors to the dots. For this, drag and drop the English Country Name from Dimensions Region to the Color field in Marks Shelf, as shown below. It means each country has its own color

Change the Size of a dots
In this example, we will show you how to change the size of the dots. For this, drag the Order Quantity from Measures Region to Size field in Marks Shelf.

Create Categorical Box Plots in Tableau
Here, we show how to create a boxplot for each color within a region. For this, drop the Color from Dimensions Region to Columns Shelf.
By default, the box plot displays the horizontal lines (or dots), and they are the compressed. Because it is difficult to draw for aggregated data, so, let’s remove the aggregated measure by unchecking the Aggregate Measures available in Analysis Menu.

Now you can see the box plot for each color present in a region.

Horizontal Tableau Box and Whisker plot
Change the default vertical into a horizontal boxplot by swapping rows and columns.
