The FTSE 250 Index (/ˈfʊtsi/ "Footsie") is a capitalisation-weighted index consisting of the 101st to the 350th largest companies listed on the London Stock Exchange, mostly covering the mid cap sector between large and small companies. The index contains a higher proportion of companies whose primary business is conducted in the UK, compared to the FTSE 100. Due to this, the FTSE 250 tends to be more representative of the strength of the UK economy than the FTSE 100.^[2] Promotions and demotions to and from the index occur quarterly in March, June, September, and December.

Related indices are the FTSE 100 Index (which lists the largest 100 companies), the FTSE 350 Index (which combines the FTSE 100 and 250), the FTSE SmallCap Index and the FTSE All-Share Index (an aggregation of the FTSE 100 Index, the FTSE 250 Index and the FTSE SmallCap Index).

The index began on 12 October 1992 at the base level of 2,403, and a market capitalisation of £98 billion. The highest closing value of 24,250.80 was reached on 1 September 2021.^[3]

The following table lists the annual changes in the FTSE 250 index.^[4][5]

Whilst the FTSE 250 had no retail products prior to its 1992 inception date, in the 1990's the index returns were back-calculated to 1986.^[6] Indicative values as follows

The following table lists the FTSE 250 companies after the changes on 15 March 2024.^[7]

• FTSE 100
• FTSE All-Share Index
• Fast Track 100 Sunday Times list of the 100 largest private (Non Listed) companies.
• Top Track 250 Sunday Times list of the 250 Mid-market (Non-Listed) companies.