Sekiwake (関脇, sekiwake) is the third highest rank in professional sumo wrestling, and is one of the san'yaku ranks. The term is believed to derive from guarding the ōzeki (大関 or 関) at his side (脇).

It represents the highest rank a wrestler can achieve by continuously making a kachikoshi (majority of wins) in tournaments. Promotion to sekiwake depends on either a space being available, which is quite common, or having a record in the previous tournament that is very convincing, typically 10–5 or better as a komusubi. There are special promotion criteria for the next highest rank of ōzeki. Unlike the higher ranks of ōzeki and yokozuna, one will lose the rank immediately after having a makekoshi tournament (more losses than wins).

For many purposes this and the komusubi rank are treated together as the junior san'yaku ranks, as opposed to ōzeki and yokozuna. For example records of number of tournaments ranked in junior san'yaku are often referred to in sumo publications.

For wrestlers reaching this rank the benefits are similar to that for a komusubi. The salary is higher than for a maegashira and also the wrestler is usually called to appear to flank the chairman of the Sumo Association during the speeches he makes on opening and closing days of the 15-day tournaments that are held six times a year. He may also be called on to represent the wrestlers on behalf of the Sumo Association at other events, especially if the number of ōzeki and yokozuna is low. If this is the highest rank a wrestler reaches, even if it is only for one tournament, he will always be referred to as "former sekiwake (ring name)" after his retirement, an indicator of a successful sumo career, even if not achieving the exceptional standards of the two highest ranks.

At any time there must be a minimum of two wrestlers ranked at sekiwake. If circumstances require, this can rise typically to three or four. The minimum of two requirement means that a certain amount of luck can lead to wrestlers achieving this rank on occasion, if the performance of other wrestlers leaves no obvious candidates to fill the rank. This luck factor is less common than it is for komusubi promotions.