The title of Senior Counsel or State Counsel (post-nominal letters: SC) is given to a senior lawyer, barrister, or advocate in some countries that were formerly part of the British Empire. "Senior Counsel" is used in current or former Commonwealth countries or jurisdictions that have chosen to change the title "Queen's Counsel" to a name without monarchical connotations, sometimes (but not always) because the British monarch is no longer head of state, such that reference to the Queen is no longer appropriate. Examples of jurisdictions which have made the change because of the latter reason include India, Hong Kong, the Republic of Ireland, South Africa, Kenya, Malawi, Singapore, Guyana and Trinidad and Tobago. Just as a junior counsel is "called to the [Outer] Bar", a Senior Counsel is, in some jurisdictions, said to be "called to the Inner Bar". Senior Counsel may informally style themselves as silks, like their British counterparts. This is the case in Ireland, Australia, Hong Kong, and South Africa.
In Hong Kong, Senior Counsel (men or women) must wear the black robe and silk gown together with a wig when appearing in open court. 
In the Republic of Ireland, Senior Counsel wear a silk's gown which differs from that of a Junior Counsel. The wig is optional in the Republic of Ireland.
The rank of Senior Counsel has also been introduced in most states and territories of Australia, even though the Queen remains head of State. Between 1993 and 2008 all Australian jurisdictions except the Northern Territory replaced the rank of Queen's Counsel with that of Senior Counsel. In 2013, however, Queensland restored the rank of Queen's Counsel and there was talk of other Australian states following suit. On 3 February 2014, the Victorian Attorney-General announced that the rank of Queen's Counsel would shortly be reinstated in Victoria, with existing and future Senior Counsel having the option to apply to be issued with letters patent appointing them as Queen's Counsel.
"Senior Counsel" (Chinese: 資深大律師) replaced QC in the law of Hong Kong after the transfer of the sovereignty of Hong Kong from the United Kingdom to China in 1997. Queen's Counsel who had been appointed QC in HK or British Queen's Counsel who had been admitted to practice in Hong Kong generally prior to the handover became Senior Counsel automatically.
Queen's Counsel from England or other senior counsel from other jurisdictions are not accorded any precedence if they are admitted generally in Hong Kong. However, visiting Queen's Counsel from another jurisdiction who have been admitted for a specific case are entitled to use the title, and to be accorded the status, of Senior Counsel for the purposes of those proceedings.
The Irish Free State became independent in 1922 as a Dominion of the British Crown. Shortly after the Courts of Justice Act 1924 came into effect, Chief Justice Hugh Kennedy in conjunction with the Bar Council of Ireland modified the procedure for issuing patents of precedence. From July 1924, "King's Counsel" was replaced by "Senior Counsel" on patents; these were issued by the Chief Justice, although the "privilege of patent" continued to fall within the royal prerogative until transferred to the Executive Council (government) by the Executive Powers (Consequential Provisions) Act 1937. The title "KC" continued to be used by many Senior Counsels, both those created before July 1924 and those after.
In 1949, shortly before the coming into force of the Republic of Ireland Act 1948 which broke the final link with the British Crown, Frank Aiken asked John A. Costello during Taoiseach's questions "whether, in view of the fact that certain members of the Inner Bar who received their patents as senior counsel continue to describe themselves as king's counsel, he will introduce a Bill entitled an Act to declare that the description of a senior counsel shall be senior counsel"; Costello said he had "no intention of wasting public time and money" on the idea.
The title "Senior Counsel" was temporarily established in New Zealand from 2007 until 2009. It was abolished by the following Government in favour of restoring the title of Queen's Counsel on the basis of the respect felt accorded to those appointed Queen's Counsel. Those appointed as Senior Counsel have been given the option of becoming Queen's Counsel or remaining as Senior Counsel.
"Senior Counsel" (in Afrikaans Senior Advokaat) replaced QC in South Africa after the Union became a Republic in 1961, with appointments being made by the State President until 1994, when the office was succeeded by that of President. A judge in the High Court in the province of Gauteng ruled that under the 1993 Constitution, the President did not have the power to grant Senior Counsel status. This judgment has been overturned by the Supreme Court of appeal and also the Constitutional Court.
Other jurisdictions have adopted similar titles:
- Senior Advocate under the law of Bangladesh, laws of India, Law of Pakistan, and that of Nigeria (see Senior Advocate of Nigeria).
- President's Counsel in Sri Lanka. (State Counsels are the public prosecutors in the legal system of Sri Lanka)
- Code of Conduct Annex 11
- "States divide over restoration of 'Queen's Counsel' title". theaustralian.com.au. Retrieved 2013-06-14.
- Victoria to give senior barristers option to become QCs
- Translation Standardisation Committee for the Chinese Media, Singapore
- See the savings and transitional provisions contained in s. 2 of Schedule 2 to Ordinance No. 94 of 1997
- Legal Practitioner's Ordinance, S.31B
- Vol.114 No.4 cols.493–5 24 February 1949
- Dáil deb Vol.521 c.191–2
- §2, Executive Powers (Consequential Provisions) Act, 1937 Irish Statute Book
- Dáil debates Vol.114 No.10 col.1448 23 March 1949
- Hall, Eamonn (April 2005). "The ancien régime" (PDF). Law Society Gazette (Law Society of Ireland) 99 (3): 14.
- "Senior Counsel Directory". Singapore Academy of Law. Retrieved 8 August 2010.
- Court rules president cannot grant senior counsel status, Mail and Guardian, February 9, 2012
- Supreme Court of India