六度分隔或六度分離（Six degrees of separation）係一個假設、猜想，話一個人識嘅一個人，即係你嘅朋友，叫第一度分隔，你識嘅朋友識嘅朋友，叫第二度分隔，如此類推，六度分隔話經過六度嘅分隔之後，全地球嘅人都連埋一齊，你同每個地球人都係隔開六度或六層，簡單啲可以咁講：「你同任何一個陌生人之間分隔開嘅人唔會多得過六個，即係話，最多通過六個人你就可以識到一個陌生人」。幾項研究，好似美國哈佛大學心理學教授 Milgram 嘅小世界實驗（en:Small world experiment），做過實驗，測吓呢個連通性。雖然確切分隔度係由人口嚟決定，結果指出分隔度數係相對細。六度分隔係「小世界現象」嘅同意詞。
六度分隔呢個理論提出之後，引起社會好大嘅關注，1990年，就有套戲劇《六度分隔》開映。1993年，同名電影《六度分隔》（Six Degrees of Separation）上畫。
- WhatIs.com has a thorough entry on the origins of the term, along with other helpful information.
- Sim6D is an online experiment based on the six degrees of separation where individuals can attempt to contact a stranger in another part of the world through their connections.
- Network for Good - a nonprofit organization where users can donate to more than one million charities and search from among more than 36,000 volunteer opportunities.
- iuGen - iuGen - The Internet User Genome Project to see how webconnected you are with your friends and their friends.
- The Million People Page - modern social networking experiment started in Feb 2006
- Six Degrees of Wikipedia - links Wikipedia articles in six degrees fashion
- E-mail Study Corroborates Six Degrees of Separation - a study by the journal Science.
- Six Degrees Black - Social networking site built on concept of Six Degrees of Separation. The site is "black" oriented.
- The Six Degrees of Kasparov - the six degrees of separation tested with Chess results.
- playtxt mososo - was the first mobile social network incorporating six degrees of separation.
- Could it be a big world? - 2001, Judith Kleinfeld, University of Alaska Fairbanks
- Connecting with people in six steps- BBC article contesting its existence
- Pumpthemusic Oracle- The 6 degrees theory applied to the musical universe
-  - The 6 degrees theory applied to movies and TV
- PDF (223 KiB), by Dan Ward - Journal article published by Defense Acquisition University, applies principles from Duncan Watts' book Six Degreesto technology innovation and scientific research.
- MySpace Page a new page to try and test out the theory of six degrees of separation whereby users add themselves to see if they come across someone they know and the author will calculate the degrees of separation.
- The Small World Experiment 54 jigsaw pieces travelling the world testing the small world theory.