Idioms about happiness

On cloud noun 

very happy and excited:

• He was on cloud nine when Rebecca was born. 
• To promote to General Manager put me on cloud nine. 

Have a whale of a time 

to enjoy yourself very much; to have a fun time: 

• We were having a whale of a time, dancing and drinking. 
• Everyone had a whale of a time at the party. 

Make someone's day 

to make someone feel very happy. 

• Her smile made my day. 
• Jessica makes my day when she sends me a postcard. 

Walk on air 

to feel extremely happy:

After he won the race, he was walking on air. 

I felt that I was walking on air when I heard the news. 

Tickled pink 

very amused or pleased about something:

• I was tickled pink to see her picture. 
• The kids were tickled pink when they were taken to the park. 

On top of the world 

extremely happy or proud:

• When I heard his good news I felt on top of the world. 
• He sent me flowers! I'm sitting on top of the world. 

Over the moon 

very happy or pleased about something: 

• He is over the moon about/with his new car. 
• Emma was over the moon about becoming an aunt. 

In seventh heaven 

extremely happy:

• She was in seventh heaven when they praised her cooking. 
• He's been in seventh heaven since she agreed to marry him.