Needless to say
Definition 1 of 1
Pro Tip 1/3Emphasizing Certainty
Use 'needless to say' to stress that what follows is very certain and expected. 
Needless to say, the well-prepared student passed the exam with flying colors.
Pro Tip 2/3Avoid Overusing
'Needless to say' should be used sparingly, or it loses impact and can annoy the listener. 
She often repeated the rules, but, needless to say, would seldom follow them herself.
Pro Tip 3/3Informal Tone
The phrase is casual and more common in spoken English than formal writing. 
Needless to say, we all went out to celebrate after the final match.