One's mantle¹ falls on somebody.春风化雨.

One's words reflect one's thinking.言为心声。

Only that which is honestly got is gain.正当的收入才是真正的收入.

Only they who fulfill² their duty in everday matters will fulfill them on great occasions.只有在日常事务上尽责的人，才能在重大事情上尽责.

Open confession³ is good for the soul.坦白交代，身心愉快.

Open not your door when the devil knocks.不要受人的诱惑.

Opportunity knock at the door only once.机不可失.

Opportunity makes the thief.疏忽招盗贼.

Opportunity, sooner or later, comes to all who work and wish.只要努力工作而有志向，机会迟早终会来临.

Other men live to eat, while I eat to live.别人为食而生活，我为生活而食.

Our affections are our life. -- We live by them; they supply our warmth.我们的感情，是我们的生命，我们靠它生存，我们的温暖是它供应.

Our best friends are they who tell us our faults and help us to mend them.最好的朋友是指出我们的缺点并帮助改正的人.

Our bravest and best lessons are not learnt through success, but through misadventure.最美好的教训不是得之于成功，而是来之于不幸.

Our greatest glory consists not in never falling, but in rising every time we fall.我们最大的光荣并不在于永不跌倒，而在于每次跌倒后能起来.

Our happiness consists not in killing⁴ others, but in sacrificing ourselves for others.我们最大幸福并不是杀害别人，而是为别人而牺牲自己.

Our own actions are our security, not others' judgements.我们的行为是自己的保证而不是别人的鉴定.

Our sweetest songs are those that tell of saddest thought.最甜美的的歌是诉说最悲伤的哀思.

Out of debt, out of danger.无债一身轻.

Out of office, out of danger.无官一身轻。

Out of sight, out of mind.久违情疏.眼不见，心不烦？

Overdone⁵ is worse than undone⁶.过犹不及.

Paddle your own canoe.自立更生，自食其力.

Pain is forgotten where gain follows.好了伤疤忘了痛.