How to Change Position of ggplot Title in R ?

In R, the ggplot2 package is widely used for creating data visualizations. One of the frequent customizations is rotating the title of a plot. The title for a ggplot2 plot defaults to left-alignment, but you might like to change its position according to the design or layout of the plot.

Adding a Title to a Plot with ggtitle()

The ggtitle() function in ggplot2 allows you to add a title to your plot.

Syntax:

ggtitle("title")

By Default the title is left aligned. Thus, if the requirement is a left-aligned title nothing much has to be done.

Example: Default Left-Aligned Title

library("ggplot2")

x<-c(1,2,3,4,5)
y<-c(10,30,20,40,35)

df<-data.frame(x,y)

ggplot(df,aes(x,y))+geom_line()+
ggtitle("Default title")

Output:

Changing the Title Position Using the theme() Function

To display the title  at any other position of the plot use theme() function. Within theme() function use plot.title parameter with element_text() function as value to it. Again within this function pass the value for hjust attribute.

Syntax: 

theme(plot.title=element_text(hjust=value))

To get the title at the center the value of hjust should be assigned to 0.5.

Example: : Center-Aligned Title

library("ggplot2")

x<-c(1,2,3,4,5)
y<-c(10,30,20,40,35)

df<-data.frame(x,y)

ggplot(df,aes(x,y))+geom_line()+
ggtitle("Title at center")+
theme(plot.title = element_text(hjust=0.5))

Output

To display title at the right, hjust should be assigned 1 as value.

Example: Right-Aligned Title

library("ggplot2")

x<-c(1,2,3,4,5)
y<-c(10,30,20,40,35)

df<-data.frame(x,y)

ggplot(df,aes(x,y))+geom_line()+ggtitle("Title at right")+
theme(plot.title = element_text(hjust=1))

Output: